The dictionary has "jaki" as "what" and "which." I thought it would not be possible to tell, by the context, which form it means, so I just chose one of them. Usually if there are multiple possible contexts, it lets you assume one of them. Can jaki mean which in a sentence like this?
I don't know the difference between which colour? and what colour?
Jaki to jest kolor ? - tell me a name of the colour, (there could be a list to pick out of, but does not have to be)
"który to jest kolor" it would feel more like there is a "pick one"
The colour on this wall is no 2456 called "midnight sunset"
Yes, maybe that's not the best word... explaining the difference between "jaki" and "co" is one of the biggest challenges that I've found here while trying to help the learners. It's just difficult to say anything without operating on specific examples.
"Co jest twój adres" doesn't make any sense. You could perhaps say: Co to jest 'twój adres'?, but that would asking for a definition of the phrase "your address".