White on pale blue sounds bad...

You might be able to find a new darker color scheme for your toolbar area on the themes page of the Add-ons site. There's a huge range from normal solid colors to frivolous designs. That hopefully will help with readability.

https://addons.mozilla.org/firefox/themes/

Normally hovering a theme will preview it, but this can be a little slow.

Regarding tab shapes or outlines, what I use is the Stylish extension and a custom style rule. It just adds a light outline to the background tabs; I also created two alternate versions for people with requested them. You can check those out here: https://userstyles.org/users/2029

If you want to try one of those, you can grab the Stylish extension from the Add-ons site:

https://addons.mozilla.org/firefox/addon/stylish/

Any luck?

Can you attach a screenshot?

• http://en.wikipedia.org/wiki/Screenshot
• https://support.mozilla.org/kb/how-do-i-create-screenshot-my-problem

• Use a compressed image type like PNG or JPG to save the screenshot
• Make sure that you do not exceed the maximum size of 1 MB

Are you using a lightweight theme (Persona)?

• https://support.mozilla.org/kb/Using+themes+with+Firefox