We discussed my enhancements to the simplex theme several times in separate forum threads, but I think it is worth to gathger all them in one post. My goal is to ask you to do all these enhancements in the source code and make them available out-of-the-box - because as we can judge from our experience after working with YAF 2.3 for some time, these enhancements can be useful for others too.
See, to produce the bootstrap-forum.min.css with my color/font preferences, I correct the following lines in the source files:
_variables.scss:
$warning: $purple !default --> change $purple to $orange
$font-size-base: 0.8125rem !default; --> change 0.8125rem to 1rem
_bootswatch.scss:
.text-secondary {color: $gray-700 !important;} --> change $gray-700 to $gray-600
Believe me, the default font size is very small and 'normal' 1rem looks much better, especially on mobile devices.
And the purple warning color does not look good with other main red/orange colors. It even does not look well in the lock sign over forum bubbles images. Compare the following screenshots took for the default color combination and mine:

Click to View Image29 View(s)

Click to View Image24 View(s)
May we expect to see these improvements in one of the future releases of your excellent forum engine?