background_over places the image over the bezel while background_under places the bezel over the image.
bg_under is the one you will want to go with for Duimon’s Graphics. bg_over is typically for images that are pre-cut ie The Bezel Project overlays.
Thank you. I was able to modify the image and that’s ready, now the problem is that since the background file is in a root folder (I assume) on my phone it won’t let me change it…ugh. I tried seeing if I could change the directory to one I can modify and that just screwed everything up. Why can nothing be straightforward :_(
I was able to figure out a workaround by copying file to the folder and removing original (it’s just it won’t let me rename files once they are withing the folder which is a weird but whatever) so now it’s working really well using Koko-aio Duimon ambilight preset, I just had to change the shader parameter to set image over content alpha channel to 0 instead of 1.
The original Duimon bezel also has a separate image just for the red lights on the mega drive console background image, and I’m curious if that could be incorporated with the ambilight preset in a way where the image layer that just has the two red lights is not affected by the ambilight affect. Is that doable? If so how would I do that?
Glad you managed to make it; on my phine, first thing I do is to move all default paths to the eternal storage.
Cx file explorer is handy to access/backup retroarch.cfg too.
The led is something I not implemented, because the number of available texture slots is limited and I think we’ve just one free left I want to reserve for future use.
Ditto on other Android devices. I do this as soon as I fire up RA for the first time. (I create the needed folders before that.)
What a nice typo 
@kokoko3k when I was looking around I found a post on stackoverflow where somebody changed a black square to a hex color. It uses the CSS filter option and an algorithm to figure out the proper settings. I thought of koko-aio since it changes a gray bezel to color.
It seems a js approach is quite convenient over using just css filters here.
I thought it was just an interesting topic because of the change from one color to another. A CSS filter would definitely not help in this instance.
Not a direct Koko-Aio question here, but I was wondering if there exist any ambilight-likr presets that use the regular Mega Bezel reflection shaders. I see that the Duimon mega bezel graphics have different layers for the background and the LED and the decal logo, etc. It would be cool if there were ambilight-like versions that I could use on my regular desktop computer that have the cool ambilight effect for the background but that have the little led console lights as a separate layer that stays lit up regardless of the ambient light from the screen, to kind of mimic more of the real world look it would have. I realize this kind of layering isn’t really a feature in the koko-aio ambilight presets, but maybe those more more heavy duty mega bezel shaders can do stuff like that?
This is planned for Mega Bezel V2, I’m going to leverage Kokoaio’s great ambilight effect as well as adding my own opinion for room bounce lighting, you can see some proto examples here
If you want to chat more about it please head over to the Mega Bezel thread 
Looks very cool, I’ll check out that thread!
Is there a way to change what background image is used depending on either the core being used or which game is being used? Seems like the problem with the method I was able to figure out to get the background I wanted required me to change the actual background image file, which is fine except if I want to use a different console it’s still uses that same background image file regardless of the shader preset. That’s just a limitation of the background that I substituted which does not have an empty square space in the middle of it unlike the console backgrounds that are built in. I suppose if I could figure out how to create precisely sized empty squares in the middle then that would work but that’s a whole separate thing I guess. If there is a fairly straightforward way to change the background image file on a per game or per console basis then that would probably be easiest for me.
Just use wildcards in your presets.
Or create multiple presets and save a core preset.
In the first post there are links to external repos hosting presets made just for the purpose you’re after; I suggest you to take a look.
The keyword you need to change in the preset you’re going to create is bg_over or bg_under.
Something like (windows example) bg_over=c:\path\to\image.png
But is this work made in Naples? CONGRATULATIONS, you did the supreme job, I tried two shaders which are spectacular, the one from Game Boy Advance, and the other I tried on Neo Geo monitor-slotmask-bloom-ShinyBezel, really amazing and works perfectly with GLCORE. THANK YOU
Made in Naples with Love 
WOWWWWWW AMAZING !! Si o nummr un ! 
Okay I think I understand. I had looked in the files and was confused by not seeing something called background_under.png, which is the name of the actual file, so I wasn’t sure what I would change. I’ll look
