Don't think you can tint the window, but you change the color of the caption bar. Create a shell script (e.g. chcap.sh) like this and put it somewhere in your PATH:
#!/bin/bash
# this is the caption I like to use. the %{kr} and %{kc}
# define the colors. See man screen for more details.
caption[0]="%{kr}%n: %t%? @%u%?%? %?%=%D-%M-%d %c"
caption[1]="%{kc}%n: %t%? @%u%?%? %?%=%D-%M-%d %c"
cur_win=$(screen -Q number | awk '{print $1}')
eval screen -X caption always \"${caption[${cur_win}]}\"
Then in your .screenrc, add this: "bind ^a eval 'exec chcap.sh' other". If you have multiple screen's running, then I think you need to add a -S or something to specify which screen.
Of course this will only work when you use C-a to switch to the other window. But in principal, you could extend it to other window switching commands and multiple windows/colors.