New empty frame with black background when using sprite sheet

For some sprite sheet, such as Game Boy / GBC - Pokémon Red / Blue - Pokémon (Menu) - The Spriters Resource, we can naturally add a new empty frame on them with transport background. But for others, such as Genesis / 32X / SCD - Sonic the Hedgehog CD (Sega CD) - Sonic the Hedgehog (Special Stage) - The Spriters Resource the new frame come as black and no transparency at all.
I wonder how do I fix this?

Also, I wonder how do I use Eyedropper to obtain the color of a certain point’s color in the sprite sheet? No wonder where I click the Eyedropper, it’s always been #000000.


Privacy & Terms