Troubleshooting Seasonal Colors Not Changing
Verifying the Resource Pack is Active
Check your resource pack settings in the main menu. Navigate to Options → Resource Packs and confirm SEASONAL TREES is in the active list on the right side. If it's in the inactive list on the left, click it and select the arrow to move it to active.
Checking Load Order
If multiple resource packs are active, SEASONAL TREES should load after any packs that modify leaves or nature blocks. Move it higher in the active list by selecting it and using the up arrow until it's near the top.
Reloading Textures
After activating the pack, press F3 + T (or Ctrl + Shift + Esc on some systems) to reload textures. This forces Minecraft to apply the resource pack changes immediately.
Multiplayer Servers
On servers, the resource pack must be installed client-side on your launcher. Server-side resource packs will override your local version. If colors still aren't changing, verify the server isn't using a conflicting resource pack that disables seasonal changes.