Ulu Vakk, of the planet Lupra, was assisting a scientist when a beam of multi-colored light from another dimension struck him, granting him his single super-ability to alter the color of an object. He came to the try-outs for a Legion of Super-Heroes position, but was rejected. He later joins the Legion of Substitute Heroes, a group formed of rejected Legion applicants. Like all of the Legion Subs, he has a Legion flight ring.
Color Kid created by Edmond Hamilton and Curt Swan
While his ability isn't the most spectacular, he has done well with the small power he has. He can change the color of objects of all sizes. He reversed the color scheme of the sky and landscape during the storyline of the Earthwar invasion. Another accomplishment was to change the color of the kryptonite cloud around Earth from green (which was deadly to Superboy and Supergirl) to blue (which was deadly to Bizarro creatures that were attacking the planet). His ability to change the color of an object is not just a superficial color change - it may alter the chemical nature of the thing itself, as with the kryptonite example. Color Kid continued to refine his abilities to the point of being able to camouflage himself and/or others, as well as confuse enemies by rapidly switching his own color, or to change the color of the air around people, effectively creating a fog of color equivalent to a darkness field.
Five Years Later
During the five years later after the Magic Wars, Color Kid stayed with the Subs until the group merged with the Legion. By then he had taken the moniker Color King.
Retroboot / New Earth
When Earth Man took over the Earth, he was faced with the Legion of Substitute Heroes at some point. During this encounter, he left Color Kid blind somehow and presumably on inactive duty after not showing up to the Subs' rescue of the Legion at the Justice League of Earth satellite.
Major Story Arcs
Color Kid becomes Color Queen
Infectious Lass infects Color Kid with "Grandin Gender Reversal Disease," causing him to change into a woman overnight. Of course, they didn't even realize the change was her fault until she infects six shuttle passengers and a customs clerk.
Powers and Abilities
Color Kid has the ability to change the color of an object at will. The exact limits of this ability are unknown but unless he reverses it, it is a permanent change. He has been shown to switch the colors of the sky and ground, temporarily confusing flying opponents. He also has demonstrated enough power to transform the color of a band of kryptonite encircling the 30th century Earth, allowing an exiled Superboy and Supergirl to return to the planet for the rest of their time as Legion members.
Color Kid can also project beams of the color black, blinding opponents in a manner similar to Shadow Lass. Color Kid continued to develop and refine his abilities throughout his career, eventually learning to disguise himself or others through a camouflage effect and confuse his opponents by switching between several colors at once.
As a member of the Legion of Substitute Heroes, Color Kid possesses a Legion Flight Ring. The ring gives its wearer the ability to fly, the speed and range of which is determined by the wearer's willpower. It also acts as a long-range communicator (enabling constant vocal contact with other Legionnaires, even across vast distances of space), a signal device, and a navigational compass, all powered by a micro-computer built inside the ring.
Superman and The Legion of Super-Heroes Animated Series
Color Kid appears in the Legion of Super Heroes animated series, where he is voiced by James Arnold Taylor.
He is portrayed as social and friendly, and at times flamboyant, but not always aware of the limits of his powers, most noticeably trying to stop an incoming attack by changing its colors - at one moment cleverly disguising himself and others, and another moment wondering if he would have impressed the Legion if he had used a different shade of green.
The most effective use of his powers came during a battle when he got Stone Boy to lie on the ground and Color Kid changed his colors to make him blend perfectly with the ground as to be almost invisible. This caused one of the villains to trip without seeing what he tripped on.