I prefer black thick PBTs too.
Word on the street is that the only thick PBTs to see general availability have been: light blue, light gray, dark gray, and white. There may have been some obscure exceptions to this in the past, but it's certainly true of anything you can find now on Taobao or eBay.
This is a frequent subject of discussion. I myself have recently participated in discussions just recently in a number of places about the options and difference between them:
http://geekhack.org/index.php?topic=40637http://geekhack.org/index.php?topic=48303http://geekhack.org/index.php?topic=48219I think that for just the Esc key if you can find a non-thick PBT in red, you'd be fine. It's such a separate key and used in such a different way that having a slightly different feel or sound shouldn't throw you off much. The only trouble is that the commonly available blank PBT sets are in cherry profile, and most one-off keys available to replace and Esc key are in OEM profile. So, even if you're able to find red PBT in a single key in red, it'll be much higher than all the rest of your keys. I have considered a number of desirable Esc key caps (e.g.,
this) but then ruled them out for this reason.
If you do find a blank red one by some miracle, please post your source here, though! I'd love to add one to my board to match the rest of my thick blanks.