I usually aim for a pink/orange as a base color 
to start mixing. (Make sure the color is more 
towards pink than orange.) Starting with colors 
commonly known as "peach" or "salmon" are good. 

Then I find I get much better results lightening 
the color if I use "unbleached titanium" white 
instead of pure white. Very light "raw umber" can 
also be used in a pinch. It just seems to add a 
depth.

If you've got bright orange, it might still be 
salvagable. . . (*thinking*) I would try mixing 
it with:

neutral gray (to kill some of the brightness)
red (to edge it towards the pink tones)
unbleached titanium (lighten to the right shade
     and it should finish killing the brightness)

Keeping in mind that it's tough to advise without 
seeing the color in front of me. ^_^;;  And you 
can't put in too much grey or you'll have zombie 
flesh tones. ^_^  If you can't use any more grey 
and it's still too neon, use a *warm* (not cold!) 
brown to damp the neon and yet still keep it in 
the "living flesh" color range. But this might 
mean a little bit more red than you would use if 
the grey worked, and you'll probably be doing 
more lightening after the fact. . .

Many Sharp Smiles,
--Drac