Color
#306bd9
#306bd9rgb(48, 107, 217)hsl(219, 69%, 52%)oklch(0.551 0.18 261.4)Colors that go with #306bd9
Charcoal, Amber 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 #306bd9: softer than #000 and cool enough to feel like part of the same palette.
Amber #ffbf00
shippedAmber is paired with #306bd9 in 11 real palettes, including Walmart's brand system and Wikipedia's brand system, as the accent.
Blue #0000ff
shipped16 real palettes, including BBC's brand system and EA's brand system put Blue beside #306bd9, as the accent.
Cobalt Blue #0047ab
shippedDesigners have shipped Cobalt Blue with #306bd9: 13 real palettes, including Carrefour's brand system and Unilever's brand system, as the accent.
Cornflower Blue #6495ed
shippedDesigners have shipped Cornflower Blue with #306bd9: 6 real palettes, including NBA's brand system and Webflow's brand system, as the accent.
Crimson #dc143c
shippedCrimson is paired with #306bd9 in 17 real palettes, including Foot Locker's brand system and Pizza Hut's brand system, as the supporting colour.
Deep Sky Blue #00bfff
shippedDesigners have shipped Deep Sky Blue with #306bd9: 7 real palettes, including Astro's brand system and Elastic's brand system, as the supporting colour.
Sienna #a0522d
split-complementshippedSienna is a split-complement of #306bd9: nearly opposite, so it still pops against it, without the vibrating edge of a true complement.
Real palettes that use #306bd9
Tints & shades
Harmonies
Contrast
| #306bd9 as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 4.96:1 | pass | pass | fail |
|
Aaon black | 4.23:1 | fail | pass | fail |
Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #306bd9 as the background.
Brands using this color
Fonts for this mood
#306bd9 reads as cool, vivid, technical. 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 #306bd9 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/306bd9-9ca5c4-df664e-211f2d-e9f0f1?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