Choosing a color scheme for the Saurus

I have a problem finding the right color scheme for some newly bought Saurus Warriors. These models will be perfect to play as Ork boyz and they look cool but how to color them? My initial idea was to paint them red with dark scales, lava meets ash. However, the results weren't what I had in mind. They need to tie in with the rest of the army, particularly the skinks, and at the same time be different enough so that they stand out on the board.

My initial idea on the right was too dark. I practised painting red with some nice highlights (middle model) but the overall feel is still too dark.

These were painted using the exact same technique as for the skinks (paint guide) and they look good but now they are almost too similar to the skinks.

Perhaps I will try to make the scales on the back a bit darker, brown for example and maybe with a pattern. I don't like the metal spikes on the back but perhaps I can simply paint them as the rest of the scales and make them dissappear.