SRB2 Wad Tranceparency Issue/Paint.net

I need help. I am making a Super Sonic wad for SRB2 but I can't get the trancperency ( I think I spelled that wrong). Anyway, I am using SlumpEd to create the lumps, paint for the sprites, and Paint.det for the trancperency. Can anyone help me with this?

Select the Magic Wand tool and then click the area you want deleted. Then press the "Delete" key on your keyboard.

What, you mean transparent in game? That transparency is different. There's this one cyan color that you need to put in the back color. You can just grab a pre-existing sprite and take the color from there. As for regular transparency (Like in my avi), you need to set tolerence to 0 first, then use the magic wand to select and delete it.

Thank yooooooou.