Calm Phosphor
Calm Phosphor (#9FA241) is a true yellow with an earthy character. It leans grounded and natural, the kind of color that plays well with wood, clay, linen, and warm neutrals. Its HSL profile (62°, 43%, 45%) places it in the balanced band at a mid lightness. It works across type, buttons, and borders, saturated enough to feel deliberate but balanced enough to not fight the rest of the palette. For a confident two-color system, pair it with its complementary blue. For something softer, pull in its analogous neighbors on either side of the wheel.
Etymology
Latin calma, heat of the day — paradoxically drifted in Italian to mean stillness. Used as a color modifier since the seventeenth century for hues that read as untroubled. Calm blue, calm gray: moderate saturation combined with optical quiet. Sits at the crisp-bucket near quiet and steady.
A chemical that emits light when excited by an external energy source — the green-and-yellow phosphors of cathode-ray tubes, the yellow phosphor coatings of fluorescent tubes, and the white-LED yellow phosphor over a blue LED. The color refers to a yellow-phosphor-coated LED at full brightness: a saturated, slightly cool yellow with the optical brightness of electroluminescent emission.
Closest matches
The nearest named color in three reference sources, ranked by perceptual distance (ΔE76 in CIELAB). ΔE < 1 is imperceptible to most viewers; ΔE > 10 is clearly different. When two sources point to the same hex they’re merged into one tile; click any to open that color’s page.
Variations
Click any swatch to exploreHarmonies
Accessibility
How this color appears to viewers with the four major color-vision-deficiency types. Computed via the Machado (2009) physiologically-based model. If a tile matches the original, the color reads the same to that viewer.
The color used as foreground text against pure white and pure black, with the contrast ratio and WCAG 2.1 grade. Aim for AA (4.5:1) for body text and AA Large (3:1) for 18 pt+ headlines; AAA (7:1) is the gold standard for long-form reading surfaces.