Conversions, palettes, contrast & design ideas for this color.
Color profile
#D66840 is a warm color from the Vermilion family, closest in name to “Koi”. In RGB it is rgb(214, 104, 64); in HSL, hsl(16, 65%, 55%).
The color Koi, with hexadecimal code #d66840, sits in the orange color family, typically linked to enthusiasm, creativity, and warmth. Orange hues stimulate appetite and social interaction, which is why food brands and community platforms favor them. Additionally, it evokes emotions such as Enthusiasm, Warmth, Motivation and Adventure. Orange is associated with spirituality and courage in some cultures, such as in Hinduism and Buddhism. In Western cultures, it often represents autumn, harvest, and creativity. At 65% saturation, this color is clearly chromatic yet balanced—colorful enough to be distinctive without overwhelming adjacent content. With a mid-range lightness of 55%, it offers excellent versatility—readable as text on light backgrounds and visible as an element on dark ones. This color is ideal for designs that aim to express Enthusiasm, Warmth, Motivation, or Adventure. It can be effectively used in web design, branding, and marketing materials to attract attention and convey specific messages.
Key facts
The story of this color
Koi (#D66840) belongs to the Vermilion color family.
This vivid mid-tone strikes the ideal balance between intensity and readability, making it a strong candidate for primary brand colors, interactive UI elements, and logo design where immediate recognition is essential.
Vermilion—a brilliant red-orange pigment—was synthesized from mercury sulfide (cinnabar) as early as 8000 BC in Anatolia. Chinese artisans perfected synthetic vermilion around the 4th century BC, using it in lacquerware, seals, and religious manuscripts. In medieval Europe, vermilion illuminated the capital letters of sacred texts, literally giving us the word 'rubric' (from Latin ruber, red).
Vermilion bridges the intensity of red with the warmth of orange, making it ideal for food and beverage branding where appetite appeal matters. It pairs well with dark olive green for autumnal themes or with navy blue for a classic nautical palette. Avoid using vermilion for error states, as users may confuse it with orange warnings.
Positioned on the warm side of the color wheel (hue 16°), it naturally draws the eye and creates a sense of closeness—making it effective for calls to action, food photography, and hospitality branding. With 65% saturation, it occupies a comfortable middle ground: colorful enough to be distinctive, yet restrained enough for extended reading or large surface areas.
Vermilion projects confidence, vitality, and creative ambition. Its warm red-orange lean makes it feel more approachable and less aggressive than pure red, which is why lifestyle and travel brands favor it for invitations to adventure.
With a mid-range lightness of 55%, this tone is highly versatile: dark enough to serve as body text on white, yet light enough to stand out on charcoal or navy backgrounds.
Use vermilion as a header accent stripe above charcoal photography for editorial impact. In interior design, a single vermilion accent wall energizes a neutral room. For digital products, vermilion hover states on cards create engaging micro-interactions.
Every format
Every way to write Koi — one-tap copy on every format; tap on any card to learn what it is and when to use it.
#D66840
Hexadecimal is the web’s universal color notation — two digits each for red, green and blue. Drop it straight into HTML, CSS or any design tool.
rgb(214, 104, 64)
RGB is the additive Red-Green-Blue model every screen uses to emit light. The default choice for websites, apps and on-screen UI.
hsl(16, 65%, 55%)
HSL breaks a color into Hue, Saturation and Lightness — the most intuitive way to lighten, darken or mute a color in CSS.
hsv(16, 70%, 84%)
HSV (also called HSB) maps Hue, Saturation and Value/Brightness. It is the model behind the color pickers in Photoshop, Figma and most design apps.
hwb(16 25% 16%)
HWB blends a pure hue with Whiteness and Blackness — a painter-friendly model added in CSS Color 4 for quick tints and shades.
cmyk(0%, 51%, 70%, 16%)
CMYK is the subtractive Cyan-Magenta-Yellow-Black ink model. Use these values when preparing artwork for a printer or commercial press.
oklch(64.15% 0.149 40.05)
OKLCH is a modern, perceptually-uniform space (Lightness, Chroma, Hue). It powers smooth gradients and accessible palettes in today’s CSS.
oklab(64.15% 0.114 0.096)
OKLab is the Cartesian form of OKLCH — ideal for blending and interpolating colors without the muddy midpoints older spaces produce.
L: 56.65, a: 40.41, b: 42.12
CIELAB is a device-independent, perceptually-uniform space. It is the standard for measuring color difference (ΔE) and matching across devices.
L: 56.65, C: 58.37, H: 46.19
LCH is CIELAB in cylindrical form — Lightness, Chroma and Hue — letting you adjust vividness and hue while staying perceptually even.
X: 33.61, Y: 24.57, Z: 7.82
CIE XYZ is the 1931 master space that underpins every other model here — the scientific bridge used to convert between color systems.
14051392
The 24-bit integer value of the color — handy for databases, APIs, game engines and low-level graphics code.
Channel breakdown
How much red, green and blue light mixes into Koi.
Percentages show each channel's share of the total light (R + G + B) in Koi.
Ink coverage
Ink needed to reproduce Koi in four-color print. Heaviest ink: Yellow.
Print tip: treat these values as a starting point — final output depends on printer profile, paper stock and calibration.
Accessibility · WCAG
How bright Koi is, and how far black and white text clear each WCAG bar.
Contrast ratio · 1:1 → 21:1 (log scale)
Developer shortcuts
Copy-and-paste CSS for Koi — per-line copy, or grab the whole block.
background-color: #D66840;
color: #D66840;
border: 2px solid #D66840;
background-color: rgb(214, 104, 64);
background-color: hsl(16, 65%, 55%);
--color: #D66840;
Shades · light to dark
Lighter and darker steps of Koi — the color's full brightness range in one strip.
The dot marks the original color. Hover any shade to copy its hex or open its color page.
Harmony · 180° apart
Two colors opposite on the wheel — maximum contrast for attention-grabbing accents.
The dot marks the original color. Hover any shade to copy its hex or open its color page.
Harmony · adjacent hues
Neighboring hues on the wheel — harmonious, calm combinations that feel unified.
The dot marks the original color. Hover any shade to copy its hex or open its color page.
Harmony · 120° apart
Three colors evenly spaced on the wheel — vibrant and energetic, yet balanced.
The dot marks the original color. Hover any shade to copy its hex or open its color page.
Harmony · 90° apart
Four colors evenly spaced on the wheel (tetradic) — rich schemes with multiple accents.
The dot marks the original color. Hover any shade to copy its hex or open its color page.
Accessibility
How Koi reads across five kinds of color vision — a ✓ Friendly verdict means the color difference stays distinguishable for that vision type.
The dot marks the original color. Hover any shade to copy its hex.
Harmony overview
The lead color from each harmony scheme, side by side — a shortcut to the full palettes above.
Perceptually nearby
A step away in brightness, richness or shade — each still feels like the same color.
From the color-name library
The closest named colors to #D66840 — same mood, each with its own character.
Looking for more Orange shades? Browse Orange colors →
Inspiration
Curated Unsplash photos that carry the mood of Koi — hover any tile to download it or view the original.
Good to know
Harmony