After a while of thinking and half-hearted converting of a DIY Space Marine Chapter ("The Emperor's Grandchildren", remenents of loyal Emperor's Children Space Marines that got lost in the wapr, etc. I know, bad idea.) I saw the old Armageddon 3 website. I took a liking to the Celestial Lions, if not for their colour scheme, then for the fact that there aren't many left to model!
I've decided that they show their company colours on their chest-eagles, and I'll be using a random colour for each Marine, showing how they've had to abandon normal squads and mix up members from different companies. The Reserve Company colours will be prominent rather than the normal company colours.
Here's a test Marine:
I know the gold is a bit dark, but I feel it looks good. Plus, I can't find the orange stuff that the other guy doing Celestial Lions has got!