3DS custom theme FAQ

There seems to be a lot unclear about this subject, so I thought it could be useful to make a FAQ about it.
If you have any questions ask them here, if you have an answer for a question you've seen a lot also post it (with the question) and I will add it to the list!

Q: How do I install a theme?
A: Download https://github.com/yellows8/3ds_homemenu_extdatatool/releases
Copy the body_LZ.bin (and bg.btstm) from the theme into /3ds/3ds_homemenu_extdatatool or to the root if you're using gateway.
Use the tool to enable cache (If you had a DLC theme selected it's already on but it doesn't hurt to check!) and then copy SD theme cache to extdata.
You can now go to the menu and the theme should appear

Q: Do I need a DLC theme for this?
A: No, but having one does have benefits! If you have a DLC theme selected and then install a custom theme it will stay after a reboot without it you'll have to enable the cache and re-install the theme every time. If you're using a gateway it should't matter as soon as gateway allows for unsigned cia's!

Q: What files should be included with a theme?
A: Most themes will come as body_LZ.bin and if it has background music with a bg.bcstm file (but they can have a ThemeManager.bin file though not common nor needed)
Cache dumps (most likely for pirated themes) will have 3 files:
- BodyCache.bin
- ThemeManager.bin
- bg.bcstm
Cache dumps of mulitible themes at once (9.3+) will have these files:
- BodyCache_rd.bin
- ThemeManger.bin
- bg.bcstm
Gateway themes will be in .cia format (but won't work unless signed!)

Q: Does this overwrite my theme?
A: No, you can choose another theme and then the original one and it will turn back to normal. This is because the tool (by Yellows8) only overwrites the cache witch is replaced when another theme is chosen!

Q: Can you pirate themes with this tool?
A: Yes. (Anyone's cache dump of a DLC theme will work (They are not version specific but BodyCache_RD.bin only works on 9.3+ all others work with any 9.x+ firmware))

Q: Are themes region locked?
A: No.

Q: How long will it keep my own custom theme?
A: If you have a DLC theme (and have it selected) before injecting cache it will stay until you either replace it or load another theme, if you don't it will stay until you close your 3DS, open a game/app or reboot your 3DS (basically useless).

Q: Can I make my own themes?
A: Yes, if you want to know how here is a simple guide by ChrisCerne:

If anyone of you is having trouble making your own theme, here's how.

1. Download the tool here (https://gbatemp.net/threads/release-theme-customization-tools.374206/)
2. Create a new BLANK BMP image with the dimensions 512 x 256 pixels for the top screen.
3. At the coordinates (0, 0) of that new image, insert the picture you want with the dimensions of 400 x 240. This will be the top screen.
4. Create a new BLANK BMP image with the dimensions 1024 x 256 pixels for the bottom screen.
5. Starting at coordinates (0, 0) of that new image, insert the three different images you want to transition on the bottom screen.
6. These three images should be each 320 x 240 pixels, and at coordinates (0, 0), (320, 0), and (640, 0) respectively.
7. Remember that these images will not fill up all of the white-space within the container BMP images. This is supposed to happen.
8. In the 3DS Theme Editor that you downloaded in step one, import the default theme by pressing File>Open and navigating to data/body_BZ.bin.
9. For slide 0, press File>Import and select the BMP Image you need for the top screen.
10. For slide 1, press File>Import and select the BMP Image you need for the bottom screen.
11. Once you're done importing, press simulator to do a test-run of your theme thus far.
12. If you're happy with your results, press File>Save to save your body_BZ.bin file.

Q: How do I add sound to my theme?
A: First make a .wav file with a piece of music (The file must have a size of 0x337000 or 3.371.008 bytes you can fill up extra space with 0 bytes using a HEX editor)
Use Every File Explorer (https://gbatemp.net/threads/release-every-file-explorer.373615/) to convert it to .bcstm (File -> New from File -> Nintendo 3DS Plugin -> CTR Stream -> open .wav -> save icon -> save as bgm.bcstm)

Q: Why do some themes have a white box at the top left?
A: This is most likely a small bug in the theme maker! You'll probably have to live with it for now.

Q: Why do many themes have folders with a mario bullet on them?
A: This is the default folder for the custom theme tool, this means that many theme makers didn't change it.

Q: Can themes have custom icons for games?
A: Most likely yes, but none have at the moment (and it's unsure when the tool will support this (and if we can even do this!))
For documentation on the cached icons that could be edited: http://3dbrew.org/wiki/Home_Menu#Cache.dat_.26_CacheD.dat

Q: Does this mean NINJHAX has kernel?
A: No, however it is able to read and write both NAND and SD extdata which is still cool (and might be useful)

 

[DoJo_Master]

Cool! We need this!

 

[endoverend]

Do you name your file body_BZ.bin or body_LZ.bin?

 

[DoJo_Master]

Do you name your file body_BZ.bin or body_LZ.bin?

LZ

 

[endoverend]

LZ

Ok because in the steps to make the theme it says BZ...

 

[ceranimo]

Guyz I don't have a gateway is there any other way to use custom themes

 

[DryTaste]

As stated in the first post, themes will stay if you use a DLC theme. Is this also the case when you go to the e-shop? Because CIA-pirated themes will uninstall when you go to the e-shop.

 

[TidusWulf]

So after a little bit of fidgeting I found I found out how to have a relatively lined up image. Just offset the top image by about 32 pixels to the right, this allows for the difference between the top and bottom to (at least seemingly) be fixed. The only thing is that it appears to get slightly worse as it goes on.

If anyone knows how to fix that problem I would like to hear.

For an example I put together a simple earth map

---------

And another view from a little later on.

--------

For use as a reference or if you just like the theme:
https://app.box.com/s/5lidiinl54x0yzdqoprw

I like this one very much. this is very well done. Thank you. Now if only I knew how to add some of my own music.

 

[Duo8]

v1.1 is out.
No longer requires theme from theme shop.

 

[Intronaut]

Now in the 1.1 version you have the option to have permanent themes without DLC.

 

[DryTaste]

Now in the 1.1 version you have the option to have permanent themes without DLC.

you didn't read the post above you did ya?

 

[endoverend]

Guyz I don't have a gateway is there any other way to use custom themes

Ninjhax

 

[Xenon Hacks]

Got it working now. Ran the wav through VGM first.

 

[Lucifer666]

Hey I'm using someone here on the temp's theme and it doesn't have a WAV file so shouldn't it just use the default audio? (or none at all?)

for some reason it keeps playing the mario theme music and it's kind of annoying

i tried re-running all those steps with the black theme set first (since it doesnt have mario music) but the problem still persists. any ideas?

 

[Xenon Hacks]

Hey I'm using someone here on the temp's theme and it doesn't have a WAV file so shouldn't it just use the default audio? (or none at all?)

for some reason it keeps playing the mario theme music and it's kind of annoying

i tried re-running all those steps with the black theme set first (since it doesnt have mario music) but the problem still persists. any ideas?

A little confused with your question try opening the theme (body_LZ.bin) in the theme editor and uncheck the "Background Music" Option and save the file, if thats what your trying to do.

 

[HEX1GON]

I get an error when enabling the cache.

I've also tried to create cache and apply it to extdata but nothing changes for me

 

[MarioBrosThe]

I have an issue where when I use the theme, and it's about the three images for the lower screen. The first image is fine and fits perfectly, but when I go the the next image on my 3ds, I can see part of the first one on it, and on the third one, I see part of the second image on it. Photoshop is confusing meh.

 

[dronesplitter]

I have an issue where when I use the theme, and it's about the three images for the lower screen. The first image is fine and fits perfectly, but when I go the the next image on my 3ds, I can see part of the first one on it, and on the third one, I see part of the second image on it. Photoshop is confusing meh.

Just be sure that when you open that image on your PC that it's 1024x256 and that you measure the first image ends at horizontal 320 pixels and the next one begins. The second image should end at 640. If there's overlap at those pixels, that's the problem. There should be white space for the bottom 16 pixels (256 is the height but only the top 240 pixels actually show) and a certain amount of white space on the right side as well.

 

[MarioBrosThe]

Just be sure that when you open that image on your PC that it's 1024x256 and that you measure the first image ends at horizontal 320 pixels and the next one begins. The second image should end at 640. If there's overlap at those pixels, that's the problem. There should be white space for the bottom 16 pixels (256 is the height but only the top 240 pixels actually show) and for a certain amount of white space on the right side as well.

OHHHH. That helps so much. Thanks dood!

 

[MarioBrosThe]

How do you make a custom folder theme?

 

[Chrisser_75]

How do you make a custom folder theme?

ustom folders are the images 2,3,4 and 5 in the template.
for example: you can open a theme with the 3DS Theme Editor -> go to body_LZ.bin -> navigate to image 2 and click on "File" -> "Export".
then you got my folder design. You can paint your own on it.