Thanks so much guys!
@Ron: the blood is made with tiny little fibers of my fiberglass pen, then I covered the fibers tips with whiteglue.
The blood has been made with Tamiya X7 clear red mixed with black.
@ Andy: the red has been made with a base of black, then I sprayed lights coats of black mixed with basic red, and I kept adding more red.
Once done I've started to add scarlet red and I've finished with napoleonic orange. As for the shadows, I've made adjustment with basic red plus Napoleonic green and at the very end black.
The trick, as far as I do, is to start witha very dark colour and work your way up to the shade of red you like the most!
Hope this helps.
Giovanni