CHANGE BACKGROUND AND FONT COLOUR OF PUTTY SCREEN
In putty , you can configure the putty background and font with multiple colours
Load the connection details from session field and then point to colours option

Uncheck the “Use system colours” checkbox and click “Default background” and click modify option to choose a background colour for your putty screen

Likewise click on “Default Foreground” option and click modify option to choose the colour you want for the foreground text

Screen looks like this after changes
