Which kind of white light usually contains relatively high amounts of yellow, orange and red?

• A. Incandescent light
• B. Fluorescent light
• C. LED light
• D. Sunlight

Answer: (A)

Warmth in white light comes from the spectrum produced by a hot filament. An incandescent bulb emits a near-continuous, blackbody-like spectrum that peaks toward the red end, so yellow, orange, and red wavelengths are relatively plentiful. That makes the light appear warm or “yellowish” white. Fluorescent and LED lights create white light differently—fluorescent sources glow due to phosphors excited by UV, giving a spectrum with distinct peaks and often a cooler appearance with less deep red. LEDs combine blue light with phosphor to produce white, which can be tuned, but it typically doesn’t have the same red-dominant warmth as incandescent. Sunlight covers all colors broadly and includes a strong blue component, yielding a neutral to cool white rather than the warm, red-rich mix of incandescent.