I have to figure out how to paint Red Scorpions space marines

I really want to use the grey and yellow on my Palanite Enforcer armour. It's possible to use silver instead which might be cool (and is also the colour scheme of my Solar Auxilia). I tried out a dark blue-grey today, but I think I'd rather do the Red Scorpions colour scheme. Just have to find a colour to do the cloth - I was doing a lighter grey than the armour, but I'd rather make it stand out a little bit. Maybe Skavenblight Dinge for more of a brownish grey tone?