Take a look at the Excel file Conditional Formatting Demonstration

Sliders control C2 and C9, spinners control C13 and C14.

Conditional Formatting is a setting applied to a cell which causes the appearance of the cell to change if a specified condition occurs.

There are two basic types of conditional formatting. One where the condition involves the value in that cell, the other where the condition is based on values from other cells around the sheet. The demonstration Excel file gives an example of each.

If C2 's value goes into the 50 - 60 range you'll see the cell's formatting change.

Click on C2, then choose Conditional Formatting on the Format menu to see the settings used.

Clicking the " Format . . . " button allows different colours to be selected.

The next slider controls C9.

C9 also has Conditional Formatting applied, but this time the condition is not dependent on C9 's own value.
C9 can be made to change its appearance based on values elsewhere in the sheet.
In this case, the values in C13 and C14. C9 's own value has no influence.
Here's the setting:

Notice that the first field in the dialogue box is set to " Formula Is ", and that, in the second field, the condition has to start with an " = " sign.
Excel needs the " = " to know that what follows is a formula, to calculate or test.

So, in this case, if C13 > C14 the alternative formatting for C9 is triggered.

In the Up & Down Game the Total changed colour if it was a multiple of 10, here's the setting for that.

MOD(F4,10) = 0 means that the total, F4, has to have a remainder of 0 when divided by 10

F4>0 because F4 must be greater than 0

AND because both these things have to be true.

( Remember the " = " is necessary in Excel when a formula is entered )