Blueprint
Open in tool →Cyan and indigo on navy is the developer-tool look; amber is the only warm note, so it always reads as 'attention'.
Color
#efc03e
#efc03e
hex
#efc03ergb
rgb(239, 192, 62)hsl
hsl(44, 85%, 59%)oklch
oklch(0.828 0.15 88)Closest name: Amber (#ffbf00)Relative luminance 0.564
Colors that go with #efc03e
Charcoal, Cornflower Blue and Deep Sky Blue lead the list. Each partner is a real named colour with the reason it works — a wheel relationship, a neutral that carries it, or a pairing lifted from a palette or brand system that actually shipped — and every pair opens in the palette tool.
Charcoal #36454f
neutralshippedCharcoal is the body-text near-black for #efc03e: its slight blue cast keeps type crisp beside a warm colour where pure #000 looks heavy.
Cornflower Blue #6495ed
complementaryshippedCornflower Blue sits directly opposite #efc03e on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight.
Deep Sky Blue #00bfff
split-complementshippedDeep Sky Blue is a split-complement of #efc03e: nearly opposite, so it still pops against it, without the vibrating edge of a true complement.
Champagne #f7e7ce
shipped4 real palettes, including Coffee Bar and Midnight Luxe put Champagne beside #efc03e, as that palette's text colour.
Crimson #dc143c
shippedCrimson is paired with #efc03e in 7 real palettes, including McDonald's's brand system and Tabloid, as the supporting colour.
Dark Olive Green #556b2f
shippedDark Olive Green shows up next to #efc03e in 4 real palettes, including Farmers Market and Miro's brand system, as the supporting colour.
Denim #1560bd
shippedDesigners have shipped Denim with #efc03e: 11 real palettes, including Wikipedia's brand system and Walmart's brand system, as the supporting colour.
Dodger Blue #1e90ff
shippedDesigners have shipped Dodger Blue with #efc03e: 7 real palettes, including Google's brand system and Heatwave, as the lead colour.
Real palettes that use #efc03e
Tints & shades
Harmonies
Contrast
| #efc03e as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 1.71:1 | fail | fail | fail | |
Aaon black | 12.28:1 | pass | pass | pass | Passes AAA — no fix needed. |
Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #efc03e as the background.
Brands using this color
Palettes built around it
Trailhead
Open in tool →Rust, pine and sun — high-visibility earth tones that read at a distance and on a trail sign.
Ember
Open in tool →Flame orange on charcoal — the sports and energy palette; one accent yellow for stats and highlights.
Fonts for this mood
#efc03e reads as warm, vivid, playful. The font library is tagged with the same vocabulary:
mcpConnect your agent — build around #efc03e
live endpointPoint any MCP client at the shared colors endpoint and your agent gets the same engine as this page — direct_palette, edit_direction, check_palette, check_contrast — read-only, no key. Every direction it proposes comes with a /colors/d/… link: open it, lock what you like, paste the link back, and the agent edits rather than re-rolls.
endpoint
https://mcp.brandsweets.com/colors/mcpclaude mcp add --transport http brandsweets-colors https://mcp.brandsweets.com/colors/mcp
try this prompt
›analyze #efc03e and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
tool url
/palettes/new/efc03e-c4be9c-62b1cb-2b2d1f-f1ebe9?lock=0&style=vibrantWant the agent to remember your picks and write them into a living brand? Create a free BrandSweets workspace.
Machine-readable: color.md