you use a own widget with explanatory text as in "No scout report" sections in standard panels or expect the text to be inserted automatically? maybe you use same id in one file
to remove the background, it is necessary to set zero transparency in the file client object browser
the other is a bit more complicated, you can start with this. it is card bg, bg, etc parameters in the color configuration file
if you thought that you will press 1 button and everything will be as you want, then it does not work like that.
you are either ready to spend hundreds or thousands of hours to make it the way you need it, or you use it as it is.
nothing is impossible
.\graphics\boxes\custom\interface\sidebar\paper.xml
red_replacement in 13 row initiate sidebar background colour, currently = sidebar
.\panels\menubar\*.xml
red_replacement in class = "picture" initiate sidebar icons colour, currently = sidebar text
.\panels\generic\sidebar menu table.xml
colour="sidebar text" initiate text colour
if your system scaling is 100%, then if you set the game scaling to 70%, it will be equivalent to the resolution of full HD with 100% game and system scaling
this is basic arithmetic
my subjective opinion is that the use of primary and secondary colors globally does not work. in rare cases it can be interesting and beautiful, but in most cases it just produces unreadable text.
believe me, if you fix it for ОМ, you will still find commands for which the text will be unreadable.