You can make a texture from scratch and only prepare it with Paintshop pro 7 ! You will save it in the end with Wally.
Make sure the image is 8 bit image (256 colors) in Paintshop pro 7 or decrease it.
Leave it like this, run optimizer
Pallete based, 0 dithering, 256 colors
(you will apply Quake 2 palette later, in the end and be sure to be 256 colors)