firefox-esr inactive tabs unreadable

[jcoles]

Using firefox-esr on RC4 as installed, I find that I cannot read the titles of inactive tabs. There is zero contrast between the text and the tab colour. Also, the + button to open a new tab is always invisible.

How do I fix this? Changing the theme (? Widget tab in Customize Look and Feel) has no effect.

[Yan]

Try changing Firefox's theme (not the system's): Tools > Add-ons and Themes > Themes > Light.