Color
#1b306a
#1b306argb(27, 48, 106)hsl(224, 59%, 26%)oklch(0.328 0.105 265.8)Colors that go with #1b306a
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 #1b306a'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 #1b306a on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight.
Blue #0000ff
shipped10 real palettes, including Alaska Airlines's brand system and Monzo's brand system put Blue beside #1b306a, as the accent.
Cadet Blue #5f9ea0
shippedDesigners have shipped Cadet Blue with #1b306a: 6 real palettes, including Open House and Coastal, as the supporting colour.
Cobalt Blue #0047ab
shippedDesigners have shipped Cobalt Blue with #1b306a: 4 real palettes, including Purina Pro Plan's brand system and Blue Mono, as the accent.
Cornflower Blue #6495ed
shippedDesigners have shipped Cornflower Blue with #1b306a: 4 real palettes, including Blue Mono and Blizzard's brand system, as the supporting colour.
Crimson #dc143c
shippedCrimson is paired with #1b306a in 10 real palettes, including Casper Sleep's brand system and Marvel's brand system, as the lead colour.
White Smoke #f5f5f5
neutralWhite Smoke is the surface for #1b306a: a clean near-white with no warm cast, so the cool hue stays clear instead of drifting muddy.
Real palettes that use #1b306a
Tints & shades
Harmonies
Contrast
| #1b306a as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 12.52:1 | pass | pass | pass | Passes AAA — no fix needed. |
Aaon black | 1.68:1 | 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 #1b306a as the background.
Brands using this color
Fonts for this mood
#1b306a reads as cool, dark, luxury. 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 #1b306a and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/1b306a-9ca2c4-df724e-221f2d-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