As with every homebrew vs commercial product comparison, both have their advantages and disadvantages. If you join the dots you will quickly realise that the extra you pay for ColorDMD is to cover the cost of the "free" library of projects - it isn't free at all, ColorDMD just offset the cost of those project files by increasing the price of their individual displays. The extra you pay is essentially for access to that library; yes, you can download any project for any game, but you can only ever install one display in any one game, so if you buy multiple displays, you pay the full price for access to that library for each display.
But the OP didn't ask for a comparison between the two products, he asked for help with his colour bleeding issue, so lets get back on topic:
Just noticed the colouring on my pin2DMD on WH2O is a bit glitchy compared to videos on YouTube. It often has random lines of colour through the score.
I've tried reseating the SD card but it's still the same. It's this an SD card issue or a DMD driver board issue?
This looks like the previous scene's last frame colour mask is bleeding into the main score; from there it will either remain on screen until some other trigger fires, or it might timeout if the timer on that colour mask frame expires and the display will revert to the projects default palette. I don't know the WW project, I know a few people have tried their hand at it over the years, but if this is Endprodukt's one then I'm surprised that the main score is not triggered. Assuming it is his project, I don't know how he triggered it; but if this was
my project I would trigger off the "ball" text which can alter it's position based on number of credits or freeplay, and also the credit dot can affect those triggers. If you can, it might be worth switching to freeplay temporarily (ie. in case he never added triggers for "credits", which is a bit thoughtless but it's possible if he only ever played in freeplay), just to see if it resolves the main score bleeding you see.
Failing that, you could try seeing if you can get hold of Endprodukt and see if there is a later version of his project you can get; I think he dropped off the radar a bit, but I'm pretty sure he has a pinside account. You can also try contacting him through this form which should go to his email:
https://pin-display.ch/artist-endprodukt/