Party planning - an art party rainbow style

My daughters birthday is on January 14th - my fault I know! It is so soon after Christmas, I have to plan it even before I have taken the decorations down which I find hard, but pinterest has definitely helped this year.
She is having an art party, so I have been looking at art party and rainbow themes, as I would like it to be bright an cheerful.

My Mother is making the cake, a palette - will post later.
I thought we could have colourful cupcakes, some cake pops and maybe macaroons.

Chocolate and sprinkle coated pretzels - they   look yummy

The style of invite I sent out for her party - very bright, not normally my style but I just love them.