We made some changes to the design of the graphs today based on the various feedback that we've received (thanks JoS users and others!).
We're definitely not done with making changes (always want to improve) but I think today's changes made a big difference.
Probably the most noticeable of them is the removal of the gradient backgrounds from the charts. We've replaced it with a solid medium blue so that they're more readable.
We've also added some light gray horizontal grid lines to help show the values of the peaks and valleys within the charts, we've made the corners square for clarity, and we've changed some of the colors that represent the websites in the graphs. (Hope that last one doesn't mess with too many people!)
Let us know if you like the changes or not.