Harbour
Open in tool →Steel blue and haze with a buoy orange on a pale grey — the maritime palette every port town uses for a reason.
Color
#305b7e
#305b7e
hex
#305b7ergb
rgb(48, 91, 126)hsl
hsl(207, 45%, 34%)oklch
oklch(0.456 0.075 245.1)Closest name: Blue Velvet (#0d6183)Relative luminance 0.0962
Colors that go with #305b7e
Sienna, Blue and Cadet 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.
Sienna #a0522d
complementaryshippedSienna sits directly opposite #305b7e on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight.
Blue #0000ff
shipped7 real palettes, including Tesco's brand system and CVS's brand system put Blue beside #305b7e, as the supporting colour.
Cadet Blue #5f9ea0
shippedDesigners have shipped Cadet Blue with #305b7e: 4 real palettes, including Open House and Dusk, as the supporting colour.
Cobalt Blue #0047ab
shippedDesigners have shipped Cobalt Blue with #305b7e: 4 real palettes, including Fintech Trust and Unilever's brand system, as the lead colour.
Crimson #dc143c
shippedCrimson is paired with #305b7e in 14 real palettes, including Codecademy's brand system and Costco's brand system, as the accent.
Denim #1560bd
shippedDesigners have shipped Denim with #305b7e: 16 real palettes, including HP's brand system and The New York Times's brand system, as the accent.
Firebrick #b22222
shippedDesigners have shipped Firebrick with #305b7e: 5 real palettes, including Fireside and Wendy's's brand system, as the lead colour.
White Smoke #f5f5f5
neutralWhite Smoke is the surface for #305b7e: a clean near-white with no warm cast, so the cool hue stays clear instead of drifting muddy.
Real palettes that use #305b7e
Tints & shades
Harmonies
Contrast
| #305b7e as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 7.18:1 | pass | pass | pass | Passes AAA — no fix needed. |
Aaon black | 2.92:1 | 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 #305b7e as the background.
Brands using this color
Palettes built around it
Fonts for this mood
#305b7e reads as cool, modern. The font library is tagged with the same vocabulary:
mcpConnect your agent — build around #305b7e
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 #305b7e and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
tool url
/palettes/new/305b7e-9cadc4-df4e53-1f212d-e9f1f1?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