Widely recognized mid-century modern Roseville pattern marked as 533-10 on the bottom and issued mid 1950's. The mottled blue color in a matte finish is quite popular and came in a variety of shapes including this leaf dish, bowls, planters, ashtrays, etc. The last of the number (-10) indicates this piece is 10-inches long. It measures 4-1/2 inches at the widest.
According to Roseville catalogs, the blue, black, pink and white colors were first introduced in 1954 and termed Late Capri. There were a total of 21 factory stock shapes. The color on this piece is blue in a bright light, but sometimes it also looks green. Familiar raised signature on the bottom. Two very tiny dark spots inside on each end (can barely be seen in the fourth picture). Under close inspection with a loupe they appear to be burn marks in the pottery. Most likely a flaw during manufacturing.