This has been an issue for a really long time, but decals are only black and white will not be visable on the site where as decals that do show up just fine.
These two decals are exactly the same except the top one has a slightly red pixel added to it.
Yep. Even when you change the background in the Toolbox to transparent or black, the images don’t show up at all. This has been bothering me for a while.