COLORS = {
    TRANSPARENT         = vec4(0.6),

    -- tones
    WHITE               = vec4(0.8, 0.8, 0.7, 1),
    BLACK               = vec4(0, 0, 0.02, 1),
    VERY_DARK_GRAY      = vec4(35/255, 35/255, 25/255, 1),
    TRUE_BLACK          = vec4(0, 0, 0, 1),

    -- non-standard hues
    WATER               = vec4(0.12, 0.25, 0.3, 1),
    GRASS               = vec4(0.10, 0.25, 0.10, 1),
    DIRT                = vec4(0.22, 0.20, 0.10, 1),
    MOUNTAIN            = vec4(0.95, 0.30, 0.20, 1),

    -- hues
    SUNRAY              = vec4(228/255, 179/255,  99/255, 1),
    MAGENTA             = vec4(      1,       0,       1, 1),
    TEAL                = vec4( 16/255, 126/255, 124/244, 1),
    YALE_BLUE           = vec4(  4/255,  75/255, 127/255, 1),
    OLIVE               = vec4(111/255, 124/254,  18/255, 1),
    LIGHT_CYAN          = vec4(224/255, 251/255, 252/255, 1),
    PALE_SILVER         = vec4(193/255, 178/255, 171/255, 1),
    CLARET              = vec4(139/255,  30/255,  63/255, 1),
    BISTRO              = vec4( 73/255,  44/255,  29/255, 1),
    DEEP_SPACE_SPARKLE  = vec4( 61/255,  90/255, 108/255, 1),
    WHEAT               = vec4(225/255, 202/255, 150/255, 1)
}