Sometimes you may find an image that looks like a sprite, but is actually a texture (usually ends in. Sometimes you'll need to change the Offset/Width/Height of the sprite in order to view it correctly.
Juniper's intro sprite and even the sprites used during the credits. If everyone looks fine, then congrats, your edit was successful! With Tinke, you can edit pretty much any sprite in the game, including things like Prof. Wait for it to finish saving, then test out your edit using an emulator. If your sprite imported correctly, Pack all the files you Unpacked, then click the Save ROM button. If you are using different colors than the ones the sprite originally had, be sure the click the 'Replace palette' option down at the Palette import options section. Save the sprite as a PNG and go to Tinke. Do not use this color in your actual sprite unless you want it to be transparent in the game. The green background is the transparency color.