Your site is well laid out, easy to find the products, uncluttered, and has exactly what it's about - could you teach everywhere else to be this good? It felt like browsing the local old-time toy shop.
Size is as-packaged, or the diameter of loose marbles. ("D" is the diameter of round items other than marbles.)
Ketchup & Mustard is a classic name for this color combination - opaque red marbles are covered with a blizzard of tiny yellow dots. The marble is about 50/50 red and yellow, with the poles revealing the base color.