Homebrew Custom themes: confused about images

[mashers]

Hi everyone

I'm making a Donkey Kong Country custom theme and I'm confused about the images for the home menu icons. I downloaded a custom theme from www.3dsthemes.com and am changing the images to DK images. Changing the wallpapers was easy enough, but I'm confused about the icon images.

There are four images for the icons: closed folder, open folder, and two different sizes for app icon backgrounds. The weird thing is that the colour palettes of these images seem to be reversed once the theme is applied. So in the original theme I used, the folder icon images (the actual BMPs exported from CustomThemeTools) were a yellowish-tan colour, and the app icon backgrounds were blue. But when the theme is applied, the folder icons are blue and the icon background are yellowish-tan! I confirmed that the same images are being used by adding text to them to mark which image was being used, and it definitely seems that the colour palettes are being reversed.

For example, I put a letter "C" on image 2, which is the closed folder image. In CustomThemeTools, this folder looks yellowish-tan and I can see the letter C on it. When I save the theme and apply it on the 3DS, the folder appears blue but still has the letter C on it. So it is as though the colour palette from the app icons is being applied to the folder icon and vice versa.

This is a problem because I want to replace the images but don't want the palettes being swapped. What can I do?

 

[mashers]

Ahh, I don't think it's swapping the palettes. I think the files are in the wrong format, according to this post:

https://gbatemp.net/threads/custom-theme-thread.377399/page-18#post-5259742

I'll experiment with changing the format and see what happens.

 

[mashers]

Confirmed - swapping the red and blue channels in the BMP solved this problem. I did this on my Mac using Pixelmator using the following process:

1. Open the Effects panel
2. Double click the Channels effect
3. In the channel mixer, select the Red tab
4. Set Red to 0% and blue to 100%
5. Select the Blue tab
6. Set Red to 100% and Blue to 0%
7. Export as BMP

The colours will look wrong in Pixelmator, and also in CustomThemeTools when you import it. But once you save the theme and install to the DS the R and B channels will be swapped back and will look normal.