Nice options for customization, I find the font size slider especially helpful. I will say, every theme is optimized for dark mode, and yet not all of the text will be light enough to read (e.g. the Work To Do section still has black text, making assignment titles practically unreadable). Because of this, it could definitely be improved by more thorough theme customization with an emphasis on color contrast.

Unfortunately, this add-on did not work for D2L Brightspace. I had high hopes, but I couldn't get the dark more or width features to work at all.