Conditional formatting that people read

Conditional formatting changes a cell's look based on its value, so the important numbers find the reader. Select a range, then Format › Conditional formatting.

• Single color rules: Less than 0 turns red, Text contains "Over" turns amber.
• Color scale shades a range from low to high. Good for heatmaps of conversion rate by week.
• Custom formula is is the powerful one. Write a formula for the top-left cell of the range, and it's copied across like any formula. =$E2>1 on A2:F20 highlights every row where column E is over 100%. The $ locks the column so every cell in the row checks E.

Rules for formatting people actually read:

• One color means one thing. If red means over budget, nothing else is red.
• Highlight the exception, not the rule. If 90% of rows are fine, color the 10% that aren't.
• Stop at two or three rules. A sheet where everything is colored says nothing.