Just a quick note to say that I tried this method again the other day on one of the few tbleague bodies I have to hand atm (s12d), and I don't know yet if it was a success or not, but I gave it a go. I finally feel I am getting the hang of the makeup sponge, at least -- I honestly think I had just been using the wrong types of sponges previously (too soft and not dense enough), and that is why I was having such trouble with blending.
My previous experiments have been with colours that are darker than the body itself. This time, I tried to use white-coloured oil pastels on a 'new suntan' tbleague body. I know, I know, I should have tried it on a pale body. But I am completely out of spending funds atm and probably will be for the next few months, so I was trying to make do with what I already have. :/ The result is that.... it took an entire stick of white oil pastel to cover just the very small areas of skin that will be showing...and I'm still not sure if it's pale enough. I probably won't know till I try it with a headsculpt, which I frustratingly don't have yet.
I also attempted a technique of applying some grey pastel onto my fingers, and then lightly rubbing that into the whitened tbleague skin. I did this because using the stick of grey directly onto the figure would have made it way too dark and streaky, and yet I still wanted to create a slightly shadowed effect. Once I applied the grey in this manner, I then went over it again with the white pastel, and blended, blended, blended. I found that if I blended long enough with the makeup sponge, I didn't really have that much residue to wash off. The final effect was indeed quite a bit paler than the original skintone, but I'm not sure if I was able to get rid of enough of the 'flesh' colour underneath it. I guess one saving grace is that the tbleague suntan is kinda weirdly grey in tone to begin with.
Ultimately, I think achieving the pale white-grey skin tone I was after would have been much easier using a white Jiaou body, or if I had just used an already-white tbleague base like the Lady Death body. But, I wanted to satisfy my curiosity. Also, I didn't really have an alternative use for this particular s12d tbleague body, as all the other headsculpts I have tried with it haven't worked (they’ve been too small for its thick neck and massive shoulders), so I figured I might as well try one more time to put it to use.
Once I have the rest of the parts for this figure, I'll have a better idea if my attempt was passable or not (and will take pics, if so), but I just thought I'd share this here in case anyone was wondering about making a tbleague figure paler, rather than darker.