Looks like the site crashed and they'll try again at 8pm, the following message is currently on their site:
#TheColorRun 北京# 致TCR北京站跑者:
由于报名系统故障,后台现已关闭,
工作人员正在努力进行系统修复,请大家耐心等待。
报名系统预计在今晚20:00重新开放。
此外,我们将采取分流报名,如在今晚仍未报名成功的跑者,
可在明天上午9:00再次报名。
Due to the registration system failure, the background is now closed
Registration system is expected to re-open at 20:00 tonight.
In addition, we will take applications in waves, so that if you cannot successfully registere tonight