Color of the caption text.
default: whiteAccepts: Azure, Beige, Black, Blue, Bronze, Brown, Coral, Crimson, Cyan, Fuchsia, Gold, Gray, Green, Indigo, Ivory, Khaki, Lavender, Lime, Magenta, Maroon, Navy, Olive, Orange, Pink, Purple, Red, Silver, Teal, Turquoise, Violet, White, Yellow