The timeline svg chart here I always find really hard to understand, and I often point clients to this and it takes them a while to make sure they have it right in their head too:
1) first and foremost there is no key which explains the different colors in the svg
2) There are 4? colors used in the chart which are all shades of the same color and used on a table which has alternating gray and white rows which further confuses things.
Compare this to the php support graph:
I find this graph with the clear colors instantly understandable