Turbo Teddy

I Need to top up my engine coolant on my 94 JDM wrx. Its green and i've been told never to mix the different colours. I have a Halfords over the road from me but they only have pink or blue. Will any of these be ok, if not can anyone tell me where to get the correct coolant from?

34srm

you carnt go off the color, drain all coolant out and replace it, only newer cars that need specific coolant , but dont mix,

Turbo Teddy

So if i drain all the coolant out, which colour would be the best to put back in?