On the G+ Carcosa group and my website, I have offered a few ideas for even more ways to make the Carcosans a bit weirder. The blogs Barnie the Flumph & Save vs Total Party Kill have also done some excellent write ups on how they make the Carcosa races different in their games.
So a few ideas:
Different Colored Blood:
To add some weird to the game, I gave each of the races different exotic colored blood in my campaign.
* Black Men: Blood: Is the color of Oxidized Bismuth.
* Blue Men: Blood: Looks like olive green tinted Mercury.
* Bone Men: Blood: Looks like a clear Aquamarine color outside the body.
* Brown Men: Blood: Looks like bright yellow-Green. (Like "The Predator".)
* Dolm Men: Blood: Looks like Brazilian Opal.
* Green Men: Blood: Looks like metallic purple.
* Jale Men: Blood: Has the color of brightly polished brass.
* Orange Men: Blood: Is a metallic turquise color.
* Purple Men: Blood: Is an orange tinted gold color.
* Red Men: Blood: Is a semi-transparent amber color.
* Ulfire Men: Blood: Is a neon brown color (Your brain hurt yet?)
* White Men: Blood: Is an oily black color.
* Yellow Men: Blood: Is a gunmetal blue color.
Eyes of the Carcosans:
Finished drawing these up this morning.