[fimoreth]

Also, why are some red & grey? Looks like it turns red at 50%.

[jeo1234]

Don't think so. Last time I looked this question was at 72 and grey, there was another which was 23 and red.

[adventured]

Any normal posts turn red at 51% and above. Ask HN posts never turn red. Went back through the top 500 posts, all of the reds are 51% or above. Might be some other variable that triggers a rare sub 51% red, but I can't find an example right now.