Help with using a box to destroy game objects

Please Guys, I needed some help with a project that I am working on. I can't figure tis out. If I have a box with four sides each with a different color(ei. black white,red, blue),and there are colored objects on the screen with the same colors . How would I get the objects to be destroyed when the face of the opposing color is shown on the box.

Please clarify your question:

What sort of box has 4 sides? Is this 2D?

What color is opposite of red? Do you mean all colors other than the one showing on the box are destroyed? Is it only when the objects touch the box?