Color
#309bc5
#309bc5rgb(48, 155, 197)hsl(197, 61%, 48%)oklch(0.648 0.112 229)Colors that go with #309bc5
Charcoal, Amber and Cobalt 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 #309bc5: softer than #000 and cool enough to feel like part of the same palette.
Amber #ffbf00
shippedAmber is paired with #309bc5 in 7 real palettes, including Beach Hut and Wired's brand system, as the supporting colour.
Cobalt Blue #0047ab
shippedDesigners have shipped Cobalt Blue with #309bc5: 4 real palettes, including Blue Mono and Hershey's's brand system, as the lead colour.
Crimson #dc143c
shippedCrimson is paired with #309bc5 in 4 real palettes, including Diner and Retro Pop, as the lead colour.
Deep Sky Blue #00bfff
shippedDesigners have shipped Deep Sky Blue with #309bc5: 5 real palettes, including Snowflake AI Data Cloud's brand system and Remix's brand system, as the supporting colour.
Denim #1560bd
shippedDesigners have shipped Denim with #309bc5: 12 real palettes, including Gopro's brand system and Coca-Cola's brand system, as the lead colour.
Light Sky Blue #87cefa
shippedLight Sky Blue is paired with #309bc5 in 4 real palettes, including Calm's brand system and Salesforce's brand system, as the supporting colour.
Chocolate #d2691e
complementaryChocolate sits directly opposite #309bc5 on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight.
Real palettes that use #309bc5
Tints & shades
Harmonies
Contrast
| #309bc5 as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 3.17:1 | fail | pass | fail | |
Aaon black | 6.62:1 | pass | 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 #309bc5 as the background.
Brands using this color
Fonts for this mood
#309bc5 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 #309bc5 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/309bc5-9cb4c4-df4e6b-1f232d-e9f1ef?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