Background color

[Yannadam]

I am completely new to Excel and have created a spreadsheet which background
should have no fill. Unfortunately, part of the spreadsheet has a gray tone
and the other no fill...Please help. I've tried changing the entire
spreadsheet to no fill

 

[Bill Kuunders]

Left click onto the cell above row 1 and to the left of column A to select
all cells.
Right click and select "format cells" opt for <no colour> and pattern
<automatic >.