Emulator

Hashless doesn't seem to have this issue (i used efb to ram while testing).

Seeing how the hashless branch is super old at this point, I tested this using the latest master (4.0-3950 as of writing) and Iriisuka branch (316a4c5), with and without EFB to RAM.
The ghosting is still there.
-KHg8m3r

This doesn't make much sense. Changing the texture cache setting should result in all textures gettting different caches than before, resulting in replacing all textures in the cache. So basically it's clears/resets the cache. This should only be required if dolphin generates the same hash for 2 different textures. Which should not happen with the safe texture cache option.

So i hope either safe texture caching fixes the problem. Or changing the graphics settings in general fixes the problem, and it's not actually texture cache related, but something else entirely.

I'm not switching from EFB from Texture to RAM while playing, I'm setting it to Texture or RAM, and then staying in that state while playing.

I have safe texture cache always on, and it still ghosts.

I'll try some other combos of settings to see if I can make it disappear.

I've found something interesting about this issue:
It doesn't happen in the very old Dolphin-win-x86-r7716 build with Direct 3D9(default settings without any changes), not sure about the other rendners but I think Direct 3D11 works too. Haven't had time to mess around with the old builds, so I can't tell if it happens with any builds before or after that, according to a different user it only works with this build.

While playing in 4.0.2 I've noticed that the effects appear even when not doing gravity moves, maybe it automatically appears whne doing tricks/going fast/when other characters do that move, but it sticks on the screen after that.

In the latest Development versions(tried 8258 & 8246, both x64) the game light goes very dark after you cross the starting line(can be seen very well in the first level of the game), I'm guessing that this effect has something to do with the gravity moves and might be linked to this.

The visual issue is no longer present. I'm not sure if the issue is fixed correctly or just the symptoms are removed though.

Started in
3.0-710 -> https://github.com/dolphin-emu/dolphin/commit/29e21026e9bf790a21f5a398d151e683196ade1e

No longer present in
5.0-1490 -> https://dolphin-emu.org/download/dev/01047319f82e6ee50e89ed8045cf713ee3ae0a56/

That looks like a legitimate fix for it, but I don't know for sure.

I am assuming these things should get cleared/invalidated. These trails remain on screen even after selecting to restart a race (before 5.0-1490).

Them being the wrong colour was maybe just a different issue that made this one visible.