Contrast ratio test fails on background gradients

[matteobelfiore]

When the test runs on pages with a gradient as a background, the background is evaluated as #ffffff. If the text colour happens to be too light —or white as well— the test obviously fails with:

Text elements should have a reasonable contrast ratio

It would probably be a good idea to pick the lightest of the gradient colours and run the test on that one instead, or on each colour separately.