How do you hook up a HD brighthouse cable box to a HD tv?

Several different ways.. First you can buy a HDMI cable( which is expensive) that cable

is the most simplest. The red, white and yellow on the HD box is the composite connection .

Another way is component which is red, green, and blue. those connections are for

video only you will need to connection your audio as well white and red . You can use the red and white audio connections from composite or component . To keep things simple use the output from the HD box to the input of your TV.