put some values in column A:A. You can use
=-100+INT(RAND()*201)
This will fill a column with random numbers from -100 to 100.

VBA Task
This one will be a teaser with If inside a loop.
Make all the cells with negative values acquire red font. Make all
positive cells with value less than 50 acquire blue font and those
above 50 acquire a green font.
In addition every 10 cells should have white background and alternate
with another 10 cells with gray background


PLEASE WRIGHT IT IN VBA