Emulator

Game Name?

Spyro: A Hero's Tail, Mario Kart: Double Dash, and Mario Kart Wii to name a few.

Game ID? (right click the game in the game list, properties, info tab)

Spyro: A Heroes Tail
G5SE7D

Mario Kart: Double Dash
GM4E01

Mario Kart Wii
RMCE01

MD5 Hash? (right click the game in the game list, properties, info tab, MD5 Hash: Compute)

Spyro: A Hero's Tail
dad9e57a1da344a7354a4b3276558eb1

Mario Kart: Double Dash
97f9ebc39ab4244e419848793988561a

Mario Kart Wii
444d0fc88aff6d50472ef0a4959b5aed

What's the problem? Describe what went wrong.

When Force 24-bit Color would possibly reduce banding, it also creates blotchy textures as a side effect.

What steps will reproduce the problem?

Start up Spyro: A Hero's Tail and go to a cave and make sure Force 24-bit Color is on.

Which versions of Dolphin did you test on? Does using an older version of Dolphin solve your issue? If yes, which versions of Dolphin used to work?

This is a day-one problem, and the fix was added in 5.0-1127, which added the option to disable Force 24-bit Color.

What are your PC specifications? (CPU, GPU, Operating System, more)

CPU: Intel(R) Core(TM) i5-4590 CPU @ 3.30GHz
GPU: AMD Radeon R9 285
RAM: 16GB DDR3
Operating System: Windows 10 Pro 64x

Is there any other relevant information? (e.g. logs, screenshots,
configuration files)

Force 24-bit Color is what causes all of the blotchy texture in Spyro: A Hero's Tail. I also observed that the setting only has a noticeable effect when it's causing defects, which is whenever alpha is stored in the framebuffer. It's more noticeable in dark areas.