1.Install 'Filter Your Screen' app from here.
2.Open the app and select 'Add Filter'.
3.Set 'Alpha' to 11, 'Red' to 127, 'Green' to 192 and 'Blue' to 0. (These are the settings I recommend, if you are not satisfied you can change accordingly.)
4.Press 'OK' and enable 'Filter 1'.
5.Finally go to...