Originally I had it hard coded to use the color of the scope “keyword”. This is just stuff I was using in testing. I changed how the region styles are associated with the bracket definition (i separated them, it makes more sense this way).
But the reason why it is white, is because everything by default is now linked to the default color scope “brackethighlighter.default”. This is how I plan to release it out of the box. You can add this scope to your color scheme file and define it to whatever color you want. Or you can change the scope to one that exists in your color scheme file, or create different scopes in your color scheme file. All brackets are probably white now (if your color scheme foreground color is white) because I am no longer defining individual colors anymore. You must do this by copying the settings file to the User folder and then change it to your hearts content.
It doesn’t make sense for me to try and define scopes for different brackets because in some color scheme files what I pick may look horrible while in others it may look good. So I created “brackethighlighter.default” (which probably does not exist in your color scheme file, which means the color will just be your foreground color).
I hope that makes sense. The plugin provides the functionality, you provide the color, style, rules etc you want. I provide some basic rules though.