Tide Pool
Open in tool →Sea-green and slate with a coral — a literal tide pool: two cool tones, one warm creature.
Color
#312d43
#312d43
hex
#312d43rgb
rgb(49, 45, 67)hsl
hsl(251, 20%, 22%)oklch
oklch(0.311 0.039 292.3)Closest name: Haiti (#2c2a35)Relative luminance 0.0293
Colors that go with #312d43
Dark Olive Green, Sea Green and Sienna 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.
Dark Olive Green #556b2f
complementaryshippedDark Olive Green sits directly opposite #312d43 on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight.
Sea Green #2e8b57
split-complementshippedSea Green is a split-complement of #312d43: nearly opposite, so it still pops against it, without the vibrating edge of a true complement.
Sienna #a0522d
split-complementshippedSienna is a split-complement of #312d43: nearly opposite, so it still pops against it, without the vibrating edge of a true complement.
Slate Blue #6a5acd
analogousshippedSlate Blue is #312d43's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces.
Steel Blue #4682b4
analogousshippedSteel Blue is #312d43's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces.
Teal #008080
triadicshippedTeal completes a triad with #312d43 — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash.
Amber #ffbf00
shippedAmber is paired with #312d43 in 9 real palettes, including Beach Hut and McDonald's's brand system, as the supporting colour.
White Smoke #f5f5f5
neutralWhite Smoke is the surface for #312d43: a clean near-white with no warm cast, so the cool hue stays clear instead of drifting muddy.
Real palettes that use #312d43
Tints & shades
Harmonies
Contrast
| #312d43 as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 13.23:1 | pass | pass | pass | Passes AAA — no fix needed. |
Aaon black | 1.59:1 | fail | fail | fail |
Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #312d43 as the background.
Brands using this color
Palettes built around it
Fonts for this mood
#312d43 reads as cool, muted, dark. The font library is tagged with the same vocabulary:
mcpConnect your agent — build around #312d43
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 #312d43 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
tool url
/palettes/new/312d43-a89cc4-dfb34e-281f2d-e9ecf1?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