Torbutton in Tor Browser 8 difficult to see in dark theme

Tor Browser 8 includes Firefox ESR 60's "dark theme". It looks quite nice and I elected to enable it. The Torbutton (used for security, and tor network settings) is difficult to see in contrast to other icons. In dark mode it'd be nice to enable a light grey version of it. Thoughts?

Trac:
Username: nsuchy

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