The pack keeps its files cleanly organised so players can build their own frog addons. Making your addon a separate pack is the safest approach because the original stays untouched.
Set up a working copy
1. Open Options > Resource Packs > Open Pack Folder.
2. Copy the Assorted Frogs pack and extract the copy if it's zipped. Never edit the original.
3. Create a new folder for your addon. Give it a pack.mcmeta file (copy the one from the original) and edit the description so you can recognise it in the menu.
4. Inside your addon, recreate the same folder path the original uses for its frog textures.
Paint and test a skin
1. Pick a frog texture from the copy and duplicate it into your addon's matching folder.
2. Open it in an image editor and recolour it. Use the existing Jungle, Chilly or Odd styles as inspiration.
3. Keep the same file name and image size. The custom frog models and animations expect the original layout, so painting over the existing areas is safest.
4. Save the file, then return to the Resource Packs screen.
5. Enable your addon and place it above Assorted Frogs X Fresh Animations so it overrides the matching texture.
6. Load a world and find a frog that uses that skin. Check that your colours show up and that the animations still look right.
If the frog looks broken or stretched, compare your image with the original. Make sure the size and layout match exactly.