In the laboratory setting, rats are commonly housed in clear caging in brightly lit rooms. As their natural history suggests a preference for low-light conditions, this practice is likely stressful for rats. As the laboratory field continues to advance, modifications and improvements to housing conditions and environment will be made. The current laboratory environment uses red tinting in shelters, doors, and for lighting under dark conditions with the conception that this does not alter the behavior or physiology of the rodents. The retinal anatomy of rats indicates they have some ability to see the red spectrum of light but that this red visibility may be limited, so red-tinted caging would replicate a darkened condition for the rodent. This talk will discuss the current laboratory lighting standards, caging conditions, and how the use of color has impact on animal welfare.