Intense, fluorescent color Color will glow under black light Milled in small batches Can be mixed with other oil paints Fluorescent oil paints have become very popular! These colors are intense and will glow under a black light! Please note that fluorescent colors are not lightfast, and paintings done with these colors should not be placed in direct sunlight. All colors can be mixed with other oil paints to produce incredibly bright and vibrant colors. This line is very professionally milled in small batches using alkali refined walnut oil blended with sun thickened walnut oil. Fluorescent colors are difficult to capture in photographs. The colors may vary slightly depending on your type of computer monitor. When dry, these colors have a matte finish.