As a student at a Waldorf school, I was taught that there are significant differences between the blood of white people and the blood of other races. Students have been taught the same at other Waldorf schools. Depending on the details, such a lesson is consistent with Steiner’s teachings. Here is a summary, taken from Steiner’s lecture “The Occult Significance of Blood”. 
Quoting Goethe’s FAUST approvingly, Steiner says “[H]e who gains power over a man's blood gains power over the man, and that blood is ‘a very special fluid’ because it is that about which, so to speak, the real fight must be waged, when it comes to a struggle concerning the man between good and evil.” 
Steiner’s premise is that everything physical reflects higher, spiritual realities, and he emphatically extends this “truth” to human blood. “Occult investigation shows decisively that all the things which surround us in this world — the mineral foundation, the vegetable covering, and the animal world — should be regarded as the physiognomical expression, or the ‘below,’ of an ‘above’ or spirit life lying behind them. From the point of view taken by occultism, the things presented to us in the sense world can only be rightly understood if our knowledge includes cognition of the ‘above,’ the spiritual archetype, the original Spiritual Beings, whence all things manifest have proceeded. And for this reason we will today apply our minds to a study of that which lies concealed behind the phenomenon of the blood, that which shaped for itself in the blood its physiognomical expression in the world of sense. When once you understand this ‘spiritual background’ of blood, you will be able to realize how the knowledge of such matters is bound to react upon our whole mental outlook on life.” 
“Questions of great importance are pressing upon us these days; questions dealing with the education, not alone of the young, but of entire nations ... [A]ll such questions are illuminated as soon as we recognize the nature of the spiritual essence which lies at the back of our blood. Who can deny that this question is closely linked to that of race, which at the present time is once more coming markedly to the front? Yet this question of race is one that we can never understand until we understand the mysteries of the blood and of the results accruing from the mingling of the blood of different races.” 
For Steiner, living in a period when European nations had extensive overseas colonies, the question of race leads to a discussion of colonial policy. “To what extent are uncivilized peoples capable of becoming civilized? How can an utterly barbaric savage become civilized? And in what way ought we to deal with them?” 
Steiner taught that all human souls are basically alike, but some are more highly evolved than others. There are low races and high races, running roughly from black to white. Humans evolve upward or downward through this hierarchy of races. In some cases, entire groups of people — even entire races — are moving upward or downward. “Those who are not aware of the conditions governing a people — whether it be on the up- or down-grade of its evolution, and whether the one or the other is a matter conditioned by its blood — such people as these will, indeed, be unlikely to hit on the right mode of introducing civilization to an alien race. These are all matters which arise as soon as the Blood Question is touched upon.” 
“[B]lood is practically fluid life.”  It has extraordinary importance. “That which is able to live in man's blood is that which lives in his ego [the highest of our three invisible bodies, our “I”]. Just as the physical body is the expression of the physical principle, as the etheric body [the lowest of our invisible bodies] is the expression of the vital fluids and their systems, and the astral body [the second of our invisible bodies] of the nervous system, so is the blood the expression of the “I,” or ego. Physical principle, etheric body, and astral body are the ‘Above’; physical body, vital system, and nervous system are the ‘below.’ Similarly, the ego is the ‘above,’ and the blood is the ‘below.’ Whoever, therefore, would master a man, must first master that man's blood. This must be borne in mind if any advance is to be made in practical life. For example, the individuality of a people may be destroyed if, when colonizing, you demand from its blood more than it can bear, for in the blood the ego is expressed. Beauty and truth possess a man only when they possess his blood.” 
Whites have blood that enables them to apprehend beauty and truth, according to Steiner. But, Steiner said, we must remember that other races are not so fortunate — we must not ask more of them than their blood allows.
These matters lead to the issue of race mixing — that is, love or, at a minimum, sexual relations between people of different races. Steiner urged great caution. Mixing the blood of different races does not lead to physical death, but it leads to a serious form of spiritual damage, depriving the higher (white) partner of his/her clairvoyant capacity — the capacity that permits apprehension of beauty and truth. Inferior races lost their clairvoyant powers through race mixing. Likewise, intellectual life (which is so inferior to occult/clairvoyance life) reflects the dire effects of race mixing. And today whites face the danger of losing their own higher clairvoyant powers:
“Modern science has discovered that if the blood of one animal is mixed with that of another not akin to it, the blood of the one is fatal to that of the other. This has been known to occultism for ages. If you mingle the blood of human beings with that of the lower apes, the result is destructive to the species, since the one is too far removed from the other. If, again, you mingle the blood of man with that of the higher apes, death does not ensue. Just as this mingling of the blood of different species of animals brings about actual death when the types are too remote, so, too, the ancient clairvoyance of undeveloped man was killed when his blood was mixed with the blood of others who did not belong to the same stock. The entire intellectual life of today is the outcome of the mingling of blood, and the time is not far distant when people will study the influence this had upon human life, and they will be able to trace it back in the history of humanity when investigations are once more conducted from this standpoint.
“We have seen that blood united to blood in the case of but remotely connected species of animals [i.e., animals that are not closely related], kills; blood united to blood in the case of more closely allied species of animals does not kill. The physical organism of man survives when strange blood comes in contact with strange blood,  but clairvoyant power perishes under the influence of this mixing of blood, or exogamy.” 
I don’t have the stomach for more of this, so I will quit. I urge you to read the rest of “The Occult Significance of Blood”. Not all of it is as bad as what we have seen, but all of it is hard on the stomach.
— Roger Rawlings
You may have noticed that I skipped from the beginning of “The Occult Significance of Blood” to the end. There's a reason. The middle of the lecture is largely consumed in reiterating basic Anthroposophical doctrines. "If we would study those mysterious laws of the spiritual universe which exist behind the blood, we must occupy ourselves a little with some of the most elementary concepts of Anthroposophy. These have often been set forth, and you will see that these elementary ideas of Anthroposophy are the ‘above,’ and that this ‘above’ is expressed in the important laws governing the blood — as well as the rest of life — as though in a physiognomy."  Whatever lectures fees Steiner received came cheaply: His lectures almost invariably recap concepts he had laid out previously, over and over and over...
On a more significant note: Anyone interested in Waldorf schools should think long and hard about the explicit link Steiner made between "concepts of Anthroposophy" and racism.
Although it has become a bit hard to find,
"The Occult Significance of Blood" is currently available from
Here is a further statement Steiner made about blood and exogamy. Appearing in a different lecture, it is, perhaps, less offensive; but it is no less occult. Key phrase: the "deterioration taking place in human blood." Steiner argues that because our blood has become tainted, it no longer carries ancient wisdom, so we now need a new approach — by which he means Anthroposophy.
"In very ancient times, as we know, endogamy was customary: people married only within the blood-related tribe. But this custom yielded increasingly to exogamy: the blood of mutually alien tribes became mixed; and that explains the decrease, the dwindling, of the heritage deriving from a remote past.
“...[E]very man bears in his own etheric body the legacy of the maternal element, and in his physical body, that of the paternal element. Now, by reason of consanguinity the inheritance, perpetuating itself from etheric body to etheric body, was very potent, and from it derived the old faculty of clairvoyance. The offspring of endogamy inherited with the related blood the old capacity for wisdom in the etheric body. But as blood became more and more mixed — as a result of increasing intermarriage among tribes — the possibility of handing down the ancient wisdom diminished; for as we said yesterday, human blood gradually altered, and the mixing of different bloods obscured the ancient wisdom more and more.
“In other words, the blood — bearer of inherited maternal attributes — became ever less fitted to transmit the old faculty of clairvoyance. It simply developed in such a way that people became ever less able to see into the spiritual world. Physically considered, therefore, human blood altered in a manner to render it increasingly incapable of bearing the old wisdom that once had guided man so surely, falling instead more and more into the opposite extreme, becoming the bearer of egotism — that is, of a quality that leads men, as egos, to individual isolation and mutual antagonism. And for the same reason it gradually lost its power of uniting men in love.
“We are, of course, still involved in this process of deterioration taking place in the human blood because, in as far as it has its origin in an ancient epoch, it will follow its lingering course to the end of Earth evolution. Therefore an impulse was needed in humanity capable of counteracting this condition. Through consanguinity men would have been led into error and misery, as the old wise men tell us in legends and myths. Men could no longer rely on the legacies of an ancient wisdom: even the oracles, asked for information and advice, divulged only what led to savage conflicts and quarrels.
“...Blood is no longer fitted to lead men upwards when it is guided only by the ancient wisdom ... This means that the primeval, inherited wisdom is not capable of saving man from the abyss into which he must fall unless a new impulse reaches mankind.” 
References to blood and its spiritual importance
are made in Anthroposophical religious services
sometimes conducted in Waldorf schools.
See "Waldorf Worship".
 Rudolf Steiner, THE OCCULT SIGNIFICANCE OF BLOOD (Rudolf Steiner Publishing Co., 1922), a lecture, GA 55. Also available from Health Research Books, 1972.
I will give the page numbers for the Health Research edition.
 pp. 5-6.
Steiner explains that studying myths, fairy tales, etc. — such as the Faust legend — can yield deep truths: “If from the new standpoint of spiritual investigation we meditate upon the old legends and myths, allowing those grand and powerful pictures which have come down from primeval times to work upon our minds, we shall find, if we have been equipped for our task by the methods of occult science, that these legends and myths are the expressions of a most profound and ancient wisdom.
“It is true we may at first be inclined to ask how it comes about that, in a primitive state of development and with primitive ideas, unsophisticated man was able to present the riddles of the universe to himself pictorially in these legends and fairy-tales; and how it is that, when we meditate on them now, we behold in them in pictorial form what the occult investigation of today is revealing to us with greater clearness.
“This is a matter which at first is bound to excite surprise. And yet he who probes deeper and deeper into the ways and means by which these fairy-tales and myths have come into being, will find every trace of surprise vanish, every doubt pass away; indeed, he will find in these legends not only what is termed a naive and unsophisticated view of things, but the wondrously deep and wise expression of a primordial and true conception of the world.
"Very much more may be learned by thoroughly examining the foundations of these myths and legends, than by absorbing the intellectual and experimental science of the present day. But for work of this kind the student must of course be familiar with those methods of investigation which belong to spiritual science. Now, all that is contained in these legends and ancient world-conceptions about the blood is wont to be of importance, since in those remote times there was a wisdom by means of which man understood the true and wide significance of blood, this “very special fluid” which is itself the flowing life of human beings.” — pp. 6-8.
 pp. 11-12.
 pp. 12-13.
 p. 13.
 p. 13.
 p. 14.
 pp. 43-44.
 In the 1922 edition, we find the following proviso added at this point: “[except, of course, in the case of incompatible blood types, which mutually coagulate one another]”.
 pp. 41-42.
 p. 16.
 Rudolf Steiner, THE GOSPEL OF ST. JOHN (Anthroposophic Press, 1948), lecture 12, GA 112.