I am just a beginner and I would like to change the format of as cell
according to a condition in another cell.

First example:I have a cell A3 that contains a text, and I want to change it
format to BOLD and change the background to BLUE when A1=M

Second example:I have a cell A3 that contains a text, and I want to change
it format to BOLD and change the background to BLUE when A1 has a GREEN
background

Please help