Rainbow with composite - MOD preset for Sega Genesis Games

Last versions are v2.9 - v2.10 and v2.11 … Pretty happy with the color tweaking here and there. v2.9 and v2.10 just keep the 95% accuracy (in my opinion) and v2.11 got more intense rainbow banding. I just found it cool to expose with more intensity these artifacts from time to time.


I just noticed that Rainbow effect doesn’t expose properly in BlastEm core, so now with v2.2 and v2.3 new variants you shall see the rainbow being exposed properly.

v2.2 will show off the 95% accurate (in my opinion) rainbow or I’d say it’s even a bit more accurate than actually it is for Genesis Plus GX. So this version have the sort of tiny rainbow lines. This version only have some dithering applied with no side CRT effects.

v2.3 have the same version from v2.2 but with intense rainbow lines if you like to see more clearly this particular effect in-game plus some CRT effects.


I explain this here. The genesis has no video artifact. Doesn’t handle transparency in hardware like the snes… What you are trying to reproduce is due to the use of bad video cabling. The genesis is rvb, and does not have a rainbow effect. Anyway I explain it here. But I respect the choice of the users, if they played like that, the nostalgia will make them prefer the bad video signal.

Explanation of the artifacts on genesis, due to a bad cabling.


I played for such a long time with RGB from earlier Sega Genesis emulators like Genecyst, kgen98 and Gens v2.14. Plus in some other seasons with 4xBRz which just enhances the RGB signal (by default in emulators) in my honest opinion … Still, there’s something beautiful about the blurry looking from 90s’ games (for me). What is looking for in this preset is to expose the rainbow effect by composite as much as I could.

I appreciate the link to explain it way better than me.

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You’re welcome my friend with pleasure. I also like the rendering, but I am French and have access to a full scart rvb signal. And when I play nes famicom, I use nestopia with the option blargg ntsc… Which degrades the video signal, generates motion and color artifacts… Because that’s how I played the nes in my childhood, because the 2 game consoles that didn’t have rvb in France are the nes famicom, and the n64. Everything else is rvb with the best quality possible. So of course I understand you, and it’s normal to want to find the nostalgia of what you knew. I respect your work, and congratulate you for sharing this with the community, I respect of course the choice of the players. Take care of yourself and thank you.

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Hello there. New rainbow presets. This time I took a sample from Hunterk for composite connection in Sega Genesis: https://www.chrismcovell.com/gotRGB/screenshots.html

v2.4 is for Genesis plus GX v2.5 is for BlastEm

Left side sample is real hardware composite from the link above and right side is Genesis plus GX


@ynnad4 v2.5 looks amazing with scanlines (overlay) and the scale2x filter on… You have taste man :ok_hand:

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The 240P in Genesis is my important and in this video they explain why.


Beat you by 2 weeks in that department (and the video):

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Are you competing for seeing who published the video before?? :laughing:

Rainbow v3.0 for Sega genesis this time buddies.

Ok so this time took another Composite sample to make another variant… This one looks almost the same to me but can’t manage to turn blue a bit lighter. If you got any ideas about another shader to incorporate, I’d appreciate it.

left side is cutted video from real sega genesis composite connection vs Genesis plus GX rainbow danny v3.0. Source video is: https://www.youtube.com/watch?v=j-G02cjXpZ0 >> Thanks to it’s author for this sample.

v3.0 rainbow (fixed up now with the correct preset file):

new update: This 2nd video may show them off better:

Rainbow is noticable in sonic&tails presentation text, now it seems that rainbow may be a bit more accurate than previous versions.



Nah mate… Just pointing out that we’re both on the same boat of seeking that “Perfect Resource-light CRT Shader”. :wink:

Granted, I’m looking for a PAL, and you’re probably looking for an NTSC one (I don’t know where you live), but we’re both still looking for one non-the-less.

Besides, call me out after you’ve tried this new version of the Rainbow Shader, I know I will.

I’m more surprised that there aren’t any Russian or French users on this forum looking for a SECAM one…


Looks great, I might just give this version a try…

You ought to get that requested to be included in the official repository…

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Tbh, the French and Russian users are more likely to just build their own shader (and post it on whatever forums they’re using ATM) :joy:

Moreso the Russians, j/s

The irony of it is that SECAM is almost exactly like PAL.

The only real difference being the colour processing spectrum both systems were using.

They usually fixed this by selling PAL games in those areas with a special PAL-SECAM Converter for their television sets.

It looked something like this:


I tried to run the shader (the 3.0 version), but it just says “Failed to apply shader preset”

Did I miss a step?

good day there buddy. Just place it in shaders folder and load the preset. It shouldn’t have any trouble. Did you do that ? And set your video driver to vulkan or opengl.

My video driver is DirectX11.

No Vulkan support, and OpenGL support is terrible.

I’m happy to release now Rainbow for sega v4.0(+v4.1). It looks very similar to the video samble. Hope you enjoy them guys. Preset is for genesis plus gx and not blastem (rainbow will be unacurrate).

Big thanks to it’s original author for uploading the sample:

Left side is a Genesis console model 2 and right side is Genesis Plus GX

You can see the beautiful rainbow colors around the letters on first picture from Sonic & Tails text presentation.

Preset variants v4.0 and v4.1 available in:


Unfortunately these preset variants only may work with .slang (vulkan or glcore). Is your GPU so old ? I have a modest graphics card and can run vulkan with no problem. video -> output -> driver -> vulkan or glcore …

My bad I just confused a bit. I meant glcore but not opengl

I use PicoDrive with the Dx11 Video Driver.

By default, all .slang shaders should work with DirectX too, but for some reason it won’t load.

Have you tried it this way yourself?

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