Am I correct that "ty" can mean both "the/those" and "you" here? Pretty interesting sentence.
No here ty means only "the/those". But can ask "Ty ty barvy vidíš?" (first ty means "you" and the second means "the/those"). ;)
But what if we ask a color-blind person? So we ask if a person generally sees colors or not. Could we use the same question meaning "ty" as "you" or it'd be better to rephrase it?
If you want to ask if someone is able to see colors, you ask: "Vidíš/Vidíte barvy?" or "Barvy vidíš/vidíte?" Or if you are surprised that some person is able to see colors, you ask "Ty vidíš/Vy vidíte barvy?"
There is no need to use the pronoun because the verb ending shows what person we talk about.