This is the only question I've found related to my topic even so it is not very clear as the solution seems to be static for that type of key and it's not explained very well how was the process of solving it: How to extend the tinymce validation rules for the style tag?

Right now I'm using TinyMCE in my project and the problem is when I have for example inline styles like:

style="height: 12mm; border: solid white 3px; background-color: [Category.FieldNumber01]"

The background changes all to lowercase, this happens with any custom style I want to use that has uppercase:

background-color: [category.fieldnumber01]

I have found solutions like getting the Category.FieldNumber01 text and before saving it into the DB make it to have uppercase again, but I want to use a general solution so it can work with any style or property

Is there a way that might be on the configuration of the styles or a function to make TinyMCE ignore styles with uppercase?

I'm new working with TinyMCE so sorry if I'm missing something important or if it is a silly question