Which heat stamp colour?

OP - Here's a pic from another thread. You can see the gold hot stamp on my mono agenda (the interior of this agenda is lighter though). IMO, the darker the leather, the better the gold will show up:

IMG_2073.jpg
 
All my heat stamping is "tone on tone" ... looks like the "Louis Vuitton Made in" stamps in look. I like it because it's discreet as a heat stamp and makes it look like that's how they made it, since it's like the other heat stamps on the bag/SLG.