Color
#306cd5
#306cd5rgb(48, 108, 213)hsl(218, 66%, 51%)oklch(0.551 0.174 260.7)Colors that go with #306cd5
Charcoal, Sienna and Amber 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 #306cd5: softer than #000 and cool enough to feel like part of the same palette.
Sienna #a0522d
complementaryshippedSienna sits directly opposite #306cd5 on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight.
Amber #ffbf00
shippedAmber is paired with #306cd5 in 11 real palettes, including Wikipedia's brand system and Walmart's brand system, as the accent.
Blue #0000ff
shipped16 real palettes, including Pixar's brand system and BBC's brand system put Blue beside #306cd5, as the accent.
Cobalt Blue #0047ab
shippedDesigners have shipped Cobalt Blue with #306cd5: 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 #306cd5: 6 real palettes, including NBA's brand system and Coca-Cola's brand system, as the accent.
Crimson #dc143c
shippedCrimson is paired with #306cd5 in 17 real palettes, including Pizza Hut's brand system and Foot Locker's brand system, as the supporting colour.
Deep Sky Blue #00bfff
shippedDesigners have shipped Deep Sky Blue with #306cd5: 7 real palettes, including Astro's brand system and Venmo's brand system, as the supporting colour.
Real palettes that use #306cd5
Tints & shades
Harmonies
Contrast
| #306cd5 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 #306cd5 as the background.
Brands using this color
Fonts for this mood
#306cd5 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 #306cd5 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/306cd5-9ca6c4-df644e-201f2d-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