So this is another Undertale OC I came up with. Thanks to xXSansTheSkeletonXx , she has a name now!
Name: Melissa or Mel for short
Age: 14

Her eyes are naturally a clear-ish grey (mine IRL), but when she sings/listens to music, not only does color "paint" the floor where she steps or touches, but her eyes turn into a rainbow's also!

Like I said earlier she can pretty much color the world, she can make anything brighter by touching it while listening to HAPPY music. The affect is reversed with sad music.

She is a huge fan of Mettaton and she loves to sing and dance alone, she has a fear of being on stage.

Her dream is to one day preform with Mettaton for all monsters in the Underground. Her best friends are Naspsatblook and Papyrus.

She is shy and sweet, doing anything she can in her power to help people/monsters. She stutters when she's upset or scared, and she is spooked easily. She has a low defense. Her attacks are either art or music related.

She has black,bfeather soft shoulder length hair. She typically wears a brown jacket with a hood, brown snow boots and dark denim jeans with a white or grey T-Shirt; and she can be found walking around Snowdin or the Waterfall.

She likes candy, sweets and sour things and hugs.

She dislikes spicy things and popcorn.

She got her powers from interacting with radioactive slime as a child. Her powers awoken, however, when her dad died at war.

She came to the Underground following Frisk to make sure they were gonna be okay. Whenever they fell, she went to go get help. They didn't believe her and she came back with rope to climb down and help Frisk.

Theme Song:
https://soundcloud.com/iamskyloud/child-of-the-highlands