BF: UI wasn't fully refreshing after changing theme

[TEParsons]

Meant you had text and buttons with the wrong colour in places, until the next time you minimise the window / restart the app.

[codecov]

Codecov Report

Attention: Patch coverage is 77.50000% with 9 lines in your changes missing coverage. Please review.

Project coverage is 50.16%. Comparing base (f2c48c4) to head (344ace0).
Report is 17 commits behind head on dev.

Additional details and impacted files

@@            Coverage Diff             @@
##              dev    #6673      +/-   ##
==========================================
+ Coverage   50.06%   50.16%   +0.09%     
==========================================
  Files         332      332              
  Lines       61143    61136       -7     
==========================================
+ Hits        30611    30668      +57     
+ Misses      30532    30468      -64     

Components	Coverage Δ
app	∅ <ø> (∅)
boilerplate	∅ <ø> (∅)
library	∅ <ø> (∅)
vm-safe library	∅ <ø> (∅)