Here are some colour combinations I came up with, but are not tested, so you might not want to try it, but still have a read over it and see if you like it:
Saim-hann
Black undercoat
codex grey all over
scab red (don't paint inbetween the joints, so the codez grey shows through, and leave the shoulder pads and head)
50/50 mix scab red and red gore(only on top of the scab red)
Red gore
50/50 mix red gore and blood red(highlights)
(if you want, blood red fine highlights, but might be a bit too much so don't try it unless you're sure)
Ghostly grey head and shoulder highlights
Alaitoc
Black undercoat
Regal blue(leave the shoulder pads and head)
Blue ink glaze, once again, not on the head or shoulder pads(water it down a fair bit, you may want to add a touch of washing up liquid to it, it collects together making it more managable)
50/50 mix regal blue and ultramarines blue(leave the last coat showing through inbetween the joints and crevices)
Ultramarines blue(highlights)
Head and shoulderpads:
Go to the GW australian web site and go to getting started on elder and how to paint elder. Follow this yellow scheme for the shoulder pads and head(you will have to paint them first an under coat of white so that the yellow inks show through or you could just use that whole colour scheme for the whole model)
If the black and white undercoats don't work together, then just use this for the shoulder pads and head:
Sunburst yellow
yellow ink glaze(don't get any on the blue, what ever you do)
Now, here's the tricky part. whatever you do now could make the model stand out really well, or make it look like a dud, so you could use this or just try your own highlights.
50/50 mix sunburst yellow and badmoons yellow(highlights
Hope all of this helps you out
Ultra Simon