Coastal
Open in tool →Sea-teal, sky and sand — bright without shouting; works for travel, wellness, and anything near water.
Color
#309c8e
#309c8e
hex
#309c8ergb
rgb(48, 156, 142)hsl
hsl(172, 53%, 40%)oklch
oklch(0.629 0.098 182.7)Closest name: Green Dynasty (#00988e)Relative luminance 0.2636
Colors that go with #309c8e
Charcoal, Copper and Crimson 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 #309c8e: softer than #000 and cool enough to feel like part of the same palette.
Copper #b87333
triadicshippedCopper completes a triad with #309c8e — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash.
Crimson #dc143c
shippedCrimson is paired with #309c8e in 8 real palettes, including Diner and Redfin's brand system, as the lead colour.
Denim #1560bd
shippedDesigners have shipped Denim with #309c8e: 8 real palettes, including Peacock and Intel's brand system, as the supporting colour.
Midnight Blue #191970
shipped7 real palettes, including Tide Pool and Ford's brand system put Midnight Blue beside #309c8e, as that palette's text colour.
Royal Blue #4169e1
shippedRoyal Blue is paired with #309c8e in 6 real palettes, including Confluent's brand system and Khan Academy's brand system, as the supporting colour.
Steel Blue #4682b4
shippedDesigners have shipped Steel Blue with #309c8e: 4 real palettes, including Ford's brand system and Fintech Trust, as the lead colour.
Taupe #483c32
shippedTaupe is paired with #309c8e in 16 real palettes, including Rain Garden and Still Water, as that palette's text colour.
Tints & shades
Harmonies
Contrast
| #309c8e as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 3.35:1 | fail | pass | fail | |
Aaon black | 6.27:1 | 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 #309c8e as the background.
Brands using this color
No public brand in the corpus uses this exact color yet. Extract a brand to add one.
Palettes built around it
Diner
Open in tool →Cherry red, mint-teal and butter yellow — chrome-and-vinyl retro; the red does the work, the teal cools it.
Tide Pool
Open in tool →Sea-green and slate with a coral — a literal tide pool: two cool tones, one warm creature.
mcpConnect your agent — build around #309c8e
live endpointPoint 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.
endpoint
https://mcp.brandsweets.com/colors/mcpclaude mcp add --transport http brandsweets-colors https://mcp.brandsweets.com/colors/mcp
try this prompt
›analyze #309c8e and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
tool url
/palettes/new/309c8e-a2bebe-d459a5-1f292d-e9f1ec?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