Same button as LP-79 and LP-80, but more of them.

Slightly warm off-white, not as warm as what we call ivory. They are about 1/16" thick and the holes are 1.5mm. Most are a bit iridescent, at least on one side. (Clearly these are not plastic buttons!)  Satiny, thick for their tiny size, durable, smooth and a bit shiny. None are grayish; that's a lighting/camera issue with the iridescence.  Most of the backs are the same; some may have a spot of seashell peach tone.  They're between 10.5 and 11mm, larger than 3/8" and just shy of 7/16".  

You'll get at least 450 buttons, for $22.00.