At Juice, we do a lot with Excel, but we never, ever, ever use the default Excel graphs. I knew Excel’s default graphs were eye-gougingly ugly, but now I can quantify at least one reason why.
Jonathan Snook has a web-based color contrast tool that shows whether two colors have appropriate contrast.
Excel’s default line chart (shown below) uses a grey background. I’ve enlarged the lines slightly to show the default line colors more clearly.
Here are the color contrast results for the grey background and the first 6 colors that Excel uses for lines. None of the first 6 colors used provides appropriate contrast with the background (NO! means there’s not enough contrast, YES! means there is—YES! Jonathan’s tool is EXUBERANT!).
Background
Color 1
Color 2
Color 3
Color 4
Color 5
Color 6
Background
na
Color 1
sort of
na
Color 2
NO!
NO!
na
Color 3
NO!
YES!
NO!
na
Color 4
NO!
sort of
NO!
NO!
na
Color 5
sort of
NO!
NO!
YES!
YES!
na
Color 6
sort of
NO!
NO!
sort of
YES
NO!
na
For those keeping score, that’s three "NO!"s and three "sort of"s when comparing the line colors to the background.
You don’t need numbers to know ugly when you see it, but it is good to know that there are usability tools out there to help you make your work easier to read.