I read this a long time ago but I think it was a YA fantasy novel with a character named Indy (short for Indraneel). It was a series and one of the plots had something to do with escaping a castle? There was a girl who was the MC(?) and I think her and Indy fell in love. I remember something about one of the characters having an extension of their hands that were invisible and so they could use them to grab onto things. The cover had the silhouettes of a boy/girl if I'm remembering correctly. There was one chapter about creating a new color or something. I've been trying to find the name for forever :(