Rainbow Pattern

School: illusion [mind-affecting]
Circle: arcane 4th, bardic 4th
Spell Components: V, S
Action Time: 1 action 
Range: medium
Shape: radius (medium)
Targeting: all (radius)
Base Duration: instant
Saving Throw: will
Spell Resistance: yes
Ritual Components: n/a

Causes a colorful, undulating array of patterns to float across the target area, fascinating up to 24 HD creatures within for 2d3+1 rounds. If caster has greater spell focus: illusion, instead lingers for 3d3+1 rounds.