COLORS = {
    TRANSPARENT         = vec4(0.6),

    -- tones
    WHITE               = vec4(1, 1, 0.95, 1),
    PALE_SILVER         = vec4(193/255, 178/255, 171/255, 1),
    BLACK               = vec4(0, 0, 0.05, 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(0.05, 0.22, 0.11, 1),
    DIRT                = vec4(0.22, 0.20, 0.10, 1),
    MOUNTAIN            = vec4(0.95, 0.30, 0.20, 1),

    -- hues
    CLARET              = vec4(139/255,  30/255,  63/255, 1),
    SUNRAY              = vec4(228/255, 179/255,  99/255, 1),
}