Hello, I need more info to help you with this.
First, what model Roku do you have (Roku 1, 2, 3, "Stick")?
Second, what type of connections are being used to the TV (RCA 3 color cables, or HDMI)?
Third, what is the model number off of the back of the TV, and what "Input" do you have the TV set to?
Are you able to see my reply?