Color
#1b306f
#1b306frgb(27, 48, 111)hsl(225, 61%, 27%)oklch(0.333 0.113 266.4)Colors that go with #1b306f
Charcoal, Steel Blue 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.
Charcoal #36454f
neutralshippedCharcoal is the text near-black for #1b306f: softer than #000 and cool enough to feel like part of the same palette.
Steel Blue #4682b4
analogousshippedSteel Blue is #1b306f's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces.
Blue #0000ff
shipped8 real palettes, including Alaska Airlines's brand system and Procter & Gamble's brand system put Blue beside #1b306f, as the accent.
Cadet Blue #5f9ea0
shippedDesigners have shipped Cadet Blue with #1b306f: 4 real palettes, including Open House and Coastal, as the supporting colour.
Cobalt Blue #0047ab
shippedDesigners have shipped Cobalt Blue with #1b306f: 4 real palettes, including Purina Pro Plan's brand system and Blue Mono, as the accent.
Crimson #dc143c
shippedCrimson is paired with #1b306f in 7 real palettes, including Casper Sleep's brand system and Marvel's brand system, as the lead colour.
Deep Sky Blue #00bfff
shippedDesigners have shipped Deep Sky Blue with #1b306f: 5 real palettes, including Kraken's brand system and Lamborghini's brand system, as the accent.
Denim #1560bd
shippedDesigners have shipped Denim with #1b306f: 18 real palettes, including Panasonic's brand system and Hasbro's brand system, as the accent.
Real palettes that use #1b306f
Tints & shades
Harmonies
Contrast
| #1b306f as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 12.36:1 | pass | pass | pass | Passes AAA — no fix needed. |
Aaon black | 1.7:1 | 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 #1b306f as the background.
Brands using this color
Fonts for this mood
#1b306f reads as cool, vivid, 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 #1b306f and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/1b306f-9ca1c4-df754e-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