Cheat Engine

[Nirojan]

so call me a faggot, because this must be simple as fuck, but google isnt telling me anything
see, I've been using photoshop elements to make the background of shit transparent and shit, but one day I accidentally clicked the background color (the shit in the color palette on the left side) and made it blue. usually it's transparent, but I made it fucking blue
so now when i delete shit to make it transparent it turns fucking blue
now it seems it would be a simple fix to make that blue go back to transparent, but i can't fucking figure out how. when I click on it, there is no opacity setting or anything, just the different colors and shit.
oh and call me a faggot for using elements if you want but I started out with it and I cbf getting cs

tl;dr
tell me how to make my background color (or foreground color) transparent again