power rings can come full spectrum, so can slimes. Let's run the list:
Red: The color of blood, these slimes are drawn to violence or displays of anger. They show up just after battles to absorb victor and victim alike. As they dissolve prey, their color deepens.
Orange: In some ways, these slimes (which have the look and consistency of pulped oranges) are the most sinister. Drawn to cheerful moods, they wait to take adventurers leaving dungeons after successful delves. Chemicals in their substance cause uncontrollable laughter in those they attack.
Yellow: Timid in their movements, these slimes feed off cowardice and fear. Fleeing adventures or monsters will draw their attention.
Green: Greed and avarice bring this species oozing out of the darkness. They tend to lie in wait around treasure troves.
Blue: Sadness and depression are the lures for these. They tend to try to trap creatures in a room for which there is no escape. They move in slowly, seeming to savior the despair as it builds.
Indigo: More rarefied in their appetites than others (if a slime can be said to be rarifed) these slime seek to absorb magic-users and others seeking transcedence through knowledge. Magic tomes and ancient inscriptions draw them. They may wait quiescent for years for a victim in the right mindset.
Violet: These slime do something positive on their own perverse way. As they flow over victims they bring calm and soothe negative emotions. This is no doubt a solace to the person so consumed.