Rudimentary Albo
Rudimentary Albo (#EFF0FC) is a soft blue with a pastel character. It reads calm and airy, with enough chroma to feel intentional rather than washed out. Its HSL profile (235°, 68%, 96%) places it in the balanced band at a light lightness. It works as a background wash, large-area fill, or soft illustration tone. Add a darker ink of the same hue when you need type over it. For a confident two-color system, pair it with its complementary yellow. For something softer, pull in its analogous neighbors on either side of the wheel.
Etymology
Latin rudīmentum, first principle — adjectival suffix -ary. As a color modifier, rudimentary implies a neutral-and-basic-and-stripped-down quality where the hue carries the visual register of prehistoric-and-cave-art rudimentary-and-foundational-mineral-pigment color-decision. Sits at the neutral-and-foundational end of the grid, parallel to basic and primal in usage.
Latin albus, white — the Virgilian poetic-color term for pure-white, particularly the Saturnian-period white-bull sacrifice-and-purification rituals. Albo color refers to a Roman-Imperial toga albens (white-toga) of Senatorial-class citizen ceremonial dress: a pure white with the matte finish of pure-white hand-spun-and-bleached fine-wool toga fabric. Cooler than cretulus (chalk-white).
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.
Wide gamut
The CSS Color 4 wide-gamut form of this color. Both swatches render the same color on every display — the P3 form only diverges from sRGB when a designer pushes channels outside sRGB's reach.
This color sits well within the sRGB cube. P3 and sRGB share the gray axis and most desaturated tones, so a P3 display renders this identically to an sRGB display.