Color
#309bd5
#309bd5rgb(48, 155, 213)hsl(201, 66%, 51%)oklch(0.656 0.127 237.6)Colors that go with #309bd5
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 #309bd5: softer than #000 and cool enough to feel like part of the same palette.
Orange Red #ff4500
split-complementshippedOrange Red is a split-complement of #309bd5: nearly opposite, so it still pops against it, without the vibrating edge of a true complement.
Amber #ffbf00
shippedAmber is paired with #309bd5 in 9 real palettes, including Heatwave and Beach Hut, as the supporting colour.
Blue #0000ff
shipped6 real palettes, including Unity's brand system and Qualcomm's brand system put Blue beside #309bd5, as the supporting colour.
Cobalt Blue #0047ab
shippedDesigners have shipped Cobalt Blue with #309bd5: 4 real palettes, including Blue Mono and Hershey's's brand system, as the lead colour.
Crimson #dc143c
shippedCrimson is paired with #309bd5 in 4 real palettes, including NASCAR's brand system and Retro Pop, as the supporting colour.
Dark Orange #ff8c00
shippedDark Orange shows up next to #309bd5 in 4 real palettes, including Elastic's brand system and Learning App, as the lead colour.
Deep Sky Blue #00bfff
shippedDesigners have shipped Deep Sky Blue with #309bd5: 5 real palettes, including Snowflake AI Data Cloud's brand system and Remix's brand system, as the supporting colour.
Real palettes that use #309bd5
Tints & shades
Harmonies
Contrast
| #309bd5 as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 3.1:1 | fail | pass | fail | |
Aaon black | 6.78:1 | 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 #309bd5 as the background.
Brands using this color
Fonts for this mood
#309bd5 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 #309bd5 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/309bd5-9cb1c4-df4e62-1f222d-e9f1f0?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