Changing colors of an ender chest with a computer.

How may I do this?

With the least amount of peripherals ofc.

I get the impression that you merely need to wrap the chest itself as a peripheral. Here's a guide covering general peripheral use, and you can find out how to get specifics about OpenPeripheral functions here.

At least, I think it's OpenPeripheral that lets you change the colours. Cheaty if you ask me, as to my understanding it doesn't require any dye items to do it.