color changing across a row

You cannot direct change the color of one or more cells with a formula
Put a formula in 'conditional formating' there it will.

Hi SGTNicholson,

You can use Conditional Formatting for this.

Select the range of cells you want to shade, let's say that's E1:J1. Let's also assume you want those cells shaded based on the value in cell A1 if cell A1 > 100.

For the CF formula, use:

=$A1>100

Set the fill color and that should take care of it.

Me or Popi?

Based on the previous assumptions (column A has the value, columns E:J need to be filled a color based on that value):

Select E1:J1 (or if multiple rows, E1:J20 for example).
Click "Conditional Formatting" on the Home bar.
Select "New Rule..."
Select "Use a formula to determine which cells to format"
Beneath "Format values where this formula is true:" type your conditional formula, e.g. =$A1>100
Click the "Format..." button
Select the "Fill" tab and select a color for shading.
Click OK twice to return to your worksheet.

If you applied that formatting to E1:J20, and A15 happened to be 121, cells E15:J15 would now be filled in with the color you chose. Hopefully that makes sense.