The color of light is measured and referred to as Kelvin. The new Lighting Facts on packaging label shows it as K.
Older incandescent bulbs colors are 2,700-3,000K, they are typically marked warm white or soft white.
For a whiter light, look for bulbs marked 3,500-4,100K, they are typically labeled cool white, natural or bright white.
For a bluer white light, look for bulbs marked 5,000-6,500K, typically labeled natural or daylight.