Lido
Open in tool →Pool blue, watermelon and sun on white — the poolside summer set; the deep teal text keeps it from going juvenile.
Color
#21a5ca
#21a5ca
hex
#21a5cargb
rgb(33, 165, 202)hsl
hsl(193, 72%, 46%)oklch
oklch(0.672 0.118 222.7)Closest name: Blue Ocean (#009dc4)Relative luminance 0.315
Colors that go with #21a5ca
Charcoal, Tomato 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 #21a5ca: softer than #000 and cool enough to feel like part of the same palette.
Tomato #ff6347
complementaryshippedTomato sits directly opposite #21a5ca 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 #21a5ca in 7 real palettes, including Salesforce's brand system and Blueprint, as the accent.
Blue #0000ff
shipped5 real palettes, including Canva's brand system and Warp's brand system put Blue beside #21a5ca, as the accent.
Denim #1560bd
shippedDesigners have shipped Denim with #21a5ca: 7 real palettes, including Gopro's brand system and Coca-Cola's brand system, as the lead colour.
Midnight Blue #191970
shipped9 real palettes, including SoFi's brand system and Confluent's brand system put Midnight Blue beside #21a5ca, as the accent.
Mustard Yellow #ffdb58
shipped4 real palettes, including Lido and Diner put Mustard Yellow beside #21a5ca, as the accent.
Orange #ffa500
shipped4 real palettes, including Gopro's brand system and Mistral AI's brand system put Orange beside #21a5ca, as the accent.
Real palettes that use #21a5ca
Tints & shades
Harmonies
Contrast
| #21a5ca as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 2.88:1 | fail | fail | fail | |
Aaon black | 7.3:1 | pass | pass | pass | Passes AAA — no fix needed. |
Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #21a5ca as the background.
Brands using this color
Palettes built around it
Fonts for this mood
#21a5ca reads as cool, vivid, technical. The font library is tagged with the same vocabulary:
mcpConnect your agent — build around #21a5ca
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 #21a5ca and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
tool url
/palettes/new/21a5ca-a2b5be-df4e75-1f242d-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