I would like to change the colors of the IDE editor. After searching the forum posts and reading everything on this topic I have tried the following:
Edit the theme.txt file.
Edit the preferences.txt file.
Copy the edited theme folder and place it in the sketch folder.
Zip the contents of the edited theme folder and place in the sketch folder.
The last attempt was the only thing that had any effect. It added the zip file to the theme menu on the preferences page. However, after selecting this and restarting the IDE the colors were the same. I am out of things to try and need some advice.
Try installing a pre-made theme to see if that will have an effect. I have a collection of them here that I know work:
Note that the .zip file installation system is a little tricky in that you have to have the right structure of the theme's .zip file. The theme must be directly in the root of the .zip file, not in a subfolder.
I downloaded one of your themes and copied it to the lib folder successfully. I thought that now all I had to do was edit the theme.txt file and I would get where I wanted to go but after seeing this file was read only I'm back where I started. I had no idea that merely changing colors would be so difficult. How did you create those themes?
ARDTECH:
I downloaded one of your themes and copied it to the lib folder successfully
My intention was for you to install the theme to the theme folder of your sketchbook to verify that it would change the colors. If the known-good theme changes the colors while your own custom theme installed via the same method does not change the colors, then you know the problem is with your custom theme, rather than something to do with the Arduino IDE or the installation method. I know the instructions I have in my repository tell you to install them to the Arduino IDE installation folder. That's because the system of being able to install themes to the sketchbook folder is relatively recent and I never got around to adding the new installation instructions. That was probably confusing.
ARDTECH:
after seeing this file was read only I'm back where I started.
It's probably that the folder where you have your Arduino IDE is installed is read only rather than the file itself.
ARDTECH:
How did you create those themes?
I started with existing themes for all of these, but they were written for either old versions of the Arduino IDE or for other IDEs (Processing, Wiring) so they all required some significant modifications. I just open the theme.txt and default.xml files in a text editor. I think I had to make some modifications of the graphics files on some of them too. That was done using Inkscape for the .svg files and GIMP for the other graphics files. The modern versions of the Arduino IDE use the .svg files. The other graphics files are for backwards compatibility with older IDE versions. If you don't care about backwards compatibility then you can just edit only the .svg files.
I installed the theme in my sketch folder and that allowed me to change most of the colors. To change the number colors I needed to edit the default.xml file. I reviewed the read file in the link you provided which gave me some insight into which commands had an effect on the IDE. I am stil a little uncertain which files/parameters affect what but at least the IDE is a little easier to read. Thanks for your help.
I'm glad to hear you are able to modify your theme now!
I have attempted to put together some documentation of the Arduino IDE's theme system here:
Note that it also hasn't been updated to account for the fact that the themes may now be installed under the sketchbook folder, but all the rest of the documentation is still good.
That project also contains a dummy library with an example sketch that shows all the theme properties in action. This makes it easy to check the contrast between the colors you chose. I found that it can be difficult to pick text colors that are easily visible both normally and when they are highlighted.