I like the look and thanks for releasing it. I think the light greys are a little too light, especially on text and inputs. I struggled to see them without straining.
Thank you for the feedback, we will see what we can improve. Most of the rules were followed from the original UI Kit but on web it seems we should do some minor changes.
I'll second this. Since in a lot of places (Canada for example), WCAG 2.0 Level AA is legally required for new commercial websites and apps, you'll be limiting your usefulness by not adhering to this.
Looks very nice - but I agree with the other feedback - text contrast needs to be reworked in some cases, for instance the warning notification. Keep in mind that different devices will have different color qualities that put some text into slightly unreadable territory, particularly smaller text.