[Enhancement] Make comments less conspicuous in light theme

[yzhang-gh]

Hi, thanks for your extension!

It would be better to make comments a bit "lighter" as now there is no contrast comparing to normal text. (Just found the line numbers seem to have the perfect color.)

At the same time, maybe we can add another color (e.g. green) so that the text is still readable.

e.g. default light+ theme (too much green)

[miguelsolorio]

Updated this for both dark and light versions and made them a bit more opaque:

Light

Dark

[yzhang-gh]

Many thanks!