Help needed in a intermission system and a color chooser

Hello there!

I have recently tried to make a game similar to color block,

I don’t know how to make a proper intermission system and a color chooser, I also want a round system where it tells who’s 1st and last, I have created the map and all of the blocks, but I don’t know how should I start coding it, I checked youtube but my help isn’t there.