Onyx Boox Poke5P User Manual page 16

Cover Color
Generally, this is to darken the
colors of large cover-style
icons.
Webpage Text Size
This is for the embedded WebView interface. When the DPI
adjustment is invalid, you can try to adjust the font size of
the webpage
Webpage Text Color
When bleaching does not work, you can try to adjust the
webpage colors.
Embolden Webpage Text
When some fonts cannot be emboldened, you can try to
embolden the webpage text.