There are many Carotenoids and they are mainly colored. The more commonly known ones are Beta Carotene (orange colored, high presence in carrots) and Lycopene (bright red colored, high presence in common tomatoes).
Crystal Tomato® Carotenoids are without colour. Colorless substances do not absorb in the visible light spectrum, they absorb at lower wavelength (i.e. UV) or higher wavelength (i.e. Infra-Red or IR).