How to connecting tv, DVD player and Riki

[st2007.sam]

How do I connect DVD player, TV and Roku (internet provider), they are all using 3 colors plug.

 

[americanaudiophile]

I will assume that your TV has only 1 AV input (Yellow video + red and white audio RCA jacks) and you need to connect two sources to it. You need an AV input selector switch.
If the DVD or Roku have HDMI use that. It will look much better than AV.