Although light sources are designed assuming the same color sensitivity for all viewers, inter-user variability can in fact cause significant discrepancies in individual perception. Here, perception variability related to short-wavelength effects is investigated. An experimental study is reported on LED sources with reduced blue content, which cause reduced circadian stimulation. Perceived chromaticity is strongly dependent on the viewer's age and spectral shape, in excellent agreement with a model based on modern colorimetry. Broader implications for LED sources in lighting and displays are discussed, and significant effects are found. These results confirm the inadequacy of conventional colorimetry and support the use of modern color science in the design and engineering of lighting products.