This rather syrupy draught must be stored in a metallic container. 

A full flask holds sufficient liquid for seven hours' effect. 

The imbiber only has to concentrate on some color or colors and he or she will turn that very hue in less than one segment.

Any color or combination of colors is possible, if the user of the magical drink simply holds the thought in his mind for the space of time required for the hues) to be effected. 

If the potion is quaffed sparingly, it is possible to get seven draughts of one hour duration apiece.