Better Cable Box?

I have charter digital cable. The only output on my boxes is coax cable. I would like to get s video out or at least the yellow rca type. Whenever bright colors are on tv there is static in the colored areas. I don't get this on DVD's. the dvd player just has the one yellow rca type cable for video but i am about to put a component cable in.

The person at charter had no clue what I was talking about when I called them.

Anyone have experience with this?

thanks