Is there a way to change background color of python-3.5 IDLE under windows 10? I've tried google and reading docs, but i can't find the answer. I'm not sure it's even possible...
For text window backgrounds, go to Options => IDLE Preferences => Highlighting tab. Save the builtin theme (both are the same) as a custom theme, with a new name. Change the background of each element with a white background to the color you want. Hit Apply or OK. Alternatively, copy the following into <HOMEDIR>/.idlerc/config-highlight.cfg (which may or may not exist already) and change #ffffff to your desired color.
[Custom Light]
normal-foreground= #000000
normal-background= #ffffff
keyword-foreground= #ff7700
keyword-background= #ffffff
builtin-foreground= #900090
builtin-background= #ffffff
comment-foreground= #dd0000
comment-background= #ffffff
string-foreground= #00aa00
string-background= #ffffff
definition-foreground= #0000ff
definition-background= #ffffff
hilite-foreground= #000000
hilite-background= gray
break-foreground= black
break-background= #ffff55
hit-foreground= #ffffff
hit-background= #000000
error-foreground= #000000
error-background= #ff7777
#cursor (only foreground can be set, restart IDLE)
cursor-foreground= black
#shell window
stdout-foreground= blue
stdout-background= #ffffff
stderr-foreground= red
stderr-background= #ffffff
console-foreground= #770000
console-background= #ffffff
We just added an IDLE Dark theme with a deep cobalt blue background. For this, leave #002240 as is or change to another dark color.
[Custom Dark]
comment-foreground = #dd0000
console-foreground = #ff4d4d
error-foreground = #FFFFFF
hilite-background = #7e7e7e
string-foreground = #02ff02
stderr-background = #002240
stderr-foreground = #ffb3b3
console-background = #002240
hit-background = #fbfbfb
string-background = #002240
normal-background = #002240
hilite-foreground = #FFFFFF
keyword-foreground = #ff8000
error-background = #c86464
keyword-background = #002240
builtin-background = #002240
break-background = #808000
builtin-foreground = #ff00ff
definition-foreground = #5e5eff
stdout-foreground = #c2d1fa
definition-background = #002240
normal-foreground = #FFFFFF
cursor-foreground = #ffffff
stdout-background = #002240
hit-foreground = #002240
comment-background = #002240
break-foreground = #FFFFFF
We are planning to add a means to change all the normal backgrounds at once. Being able to affect dialogs will be a later project.