Color
#309db5
#309db5rgb(48, 157, 181)hsl(191, 58%, 45%)oklch(0.646 0.101 215.9)Colors that go with #309db5
Charcoal, Orange Red 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 #309db5: softer than #000 and cool enough to feel like part of the same palette.
Orange Red #ff4500
complementaryshippedOrange Red sits directly opposite #309db5 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 #309db5 in 4 real palettes, including Beach Hut and Wired's brand system, as the supporting colour.
Cobalt Blue #0047ab
shippedDesigners have shipped Cobalt Blue with #309db5: 4 real palettes, including Hershey's's brand system and Fintech Trust, as the supporting colour.
Copper #b87333
shippedDesigners have shipped Copper with #309db5: 4 real palettes, including Dusk and Clean Beauty, as the accent.
Cornflower Blue #6495ed
analogousshippedCornflower Blue is #309db5's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces.
Crimson #dc143c
shippedCrimson is paired with #309db5 in 6 real palettes, including Diner and Redfin's brand system, as the lead colour.
Deep Sky Blue #00bfff
shippedDesigners have shipped Deep Sky Blue with #309db5: 6 real palettes, including Telegram's brand system and Snowflake AI Data Cloud's brand system, as the lead colour.
Real palettes that use #309db5
Tints & shades
Harmonies
Contrast
| #309db5 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 #309db5 as the background.
Brands using this color
No public brand in the corpus uses this exact color yet. Extract a brand to add one.
Fonts for this mood
#309db5 reads as cool, modern. 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 #309db5 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/309db5-a2b6be-df4e7a-1f252d-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