4
a. Now go to Image>Mode>Indexed Color...
click "ok" when it asks "Merge Layers"
use these settings
b. Now go to Image>Mode>Color Table...

Click on the last square, When the color prompt comes up, choose pure blue (0,0,255)

c. Now go to File>Save As...

You can close Photoshop now, Open up the file in Wally