Ive got the head apart from a 1.8 silvertop zetec

In the new headset, there is a packet with a set of new valve stem oil seals. Does anyone know why half of them are a different colour? They look exactly the same- not sure if it matters what ones go what side

And also, there are a set of small rubber seals. I didnt take any of these off when i stripped the head. Only thing i cam think is that the slide over the valve guide before the main seal?





Any help or advise appreciated!