Sense Shifting

Sense shifting allows the wizard to affect all spells of levels 1 through 3 that he casts within the duration of the spell. For each spell, he can modify one of three sensory features pertaining to the spell: color, sound, or patterned visual appearance of the spell effect. The changes produced by this spell do not affect the functions of the affected spell nor any saving throws that apply against their effects.
Sense shifting might be used to produce green Fireballs, Magic Missiles that streak through the air with a scream, colored continual light globes, customized designs for a Hypnotic Pattern, or a Spectral Hand that makes scrabbling sounds as it attempts to grasp a target.
Sense shifting cannot create any form of invisibility. It cannot completely silence a spell effect (thus, a fireball's blast might be muted, but not wholly eliminated).

[Tome of Magic]

School: Alteration
Level: 2
Rarity: Uncommon

Range: 0
Components: V, S, M
Duration: 3 turns
Casting Time: 2
Area of Effect: The caster
Saving Throw: None

Material Components:
a twist of multicolored ribbon with a small silver bell fastened to its end