So, the program applies HSV in the regular range straight on the images. The reason you can only darken the items and not make them lighter is they are not exported in “white”, they already have colors which can’t be removed with HSVing. We could’ve exported all the images which are colorable without actual colors, only shades, but we didn’t think of it two years ago when we added this option. We also wanted each item to have it’s own character while giving you the flexibility to fine tune it’s color. I’ll have a look if we can make it better in the future, but I’m afraid it’s not easily solvable without re-exporting every item we have retroactively without any coloring upfront. It’s something that’s easy to change in various photo editing softwares, but not a trivial one to solve in code by being able to only manipulate pixels in a given way.