Chromatic Dragonborn

Races that are not Large nor have an innate flying speed gain an extra Feat of their choice. This Feat must be a "Full Feat".

Your character can speak, read, and write Common and one other language of your choice. 

You gain 3 ability points to increase any abilities of your choice. You can't increase a single ability by more than 2 with these points.

You have a chromatic dragon ancestor, granting you a special magical affinity. Choose one kind of dragon below. This determines the damage type for your other traits.

Black - Acid

Blue - Lightning

Green - Poison

Red - Fire

White - Cold

As an action, you can exhale a breath attack in a 30-foot line that is 5 feet wide. Each creature in that area must make a Dexterity saving throw (DC is equal to either your Mastery Save DC or Spell Save DC). On a failed save, the creature takes 1d10 damage of the type associated with your Chromatic Ancestry. On a successful save, it takes half as much damage. This damage increases by 1d10 when you reach 5th level (2d10), 11th level (3d10), and 17th level (4d10).

You can use your Breath Weapon a number of times equal to your proficiency bonus, and you regain all expended uses when you finish a long rest.

You have resistance to the damage type associated with your Chromatic Ancestry. 

Starting at 5th level, as an action, you can channel your draconic energy to protect yourself. For 1 minute, you become immune to the damage type associated with your Chromatic Ancestry. Once you use this trait, you can’t do so again until you finish a long rest.