Color
#313f63
#313f63rgb(49, 63, 99)hsl(223, 34%, 29%)oklch(0.373 0.065 267.1)Colors that go with #313f63
Steel Blue, Dark Olive Green and 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.
Steel Blue #4682b4
analogousshippedSteel Blue is #313f63's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces.
Dark Olive Green #556b2f
complementaryshippedDark Olive Green sits directly opposite #313f63 on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight.
Blue #0000ff
shipped9 real palettes, including Alaska Airlines's brand system and Dunkin''s brand system put Blue beside #313f63, as the accent.
Blush Pink #e8b4b8
shipped4 real palettes, including Nursery and Garden Wedding put Blush Pink beside #313f63, as the lead colour.
Cadet Blue #5f9ea0
shippedDesigners have shipped Cadet Blue with #313f63: 5 real palettes, including Open House and Coastal, as the supporting colour.
Copper #b87333
shippedDesigners have shipped Copper with #313f63: 5 real palettes, including Notion's brand system and Clean Beauty.
Crimson #dc143c
shippedCrimson is paired with #313f63 in 7 real palettes, including Codecademy's brand system and Marvel's brand system, as the accent.
White Smoke #f5f5f5
neutralWhite Smoke is the surface for #313f63: a clean near-white with no warm cast, so the cool hue stays clear instead of drifting muddy.
Real palettes that use #313f63
Tints & shades
Harmonies
Contrast
| #313f63 as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 10.39:1 | pass | pass | pass | Passes AAA — no fix needed. |
Aaon black | 2.02:1 | 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 #313f63 as the background.
Brands using this color
Fonts for this mood
#313f63 reads as cool, muted, dark. The font library is tagged with the same vocabulary:
Point 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.
https://mcp.brandsweets.com/colors/mcpclaude mcp add --transport http brandsweets-colors https://mcp.brandsweets.com/colors/mcp
›analyze #313f63 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/313f63-9ca3c4-df704e-211f2d-e9eff1?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