Heatwave
Open in tool →Blaze orange and hot yellow with one cold blue — the high-noon palette; use the blue where the eye needs to rest.
Color
#398efergb(57, 142, 254)hsl(214, 99%, 61%)oklch(0.653 0.185 256.8)Charcoal, Medium Sea Green and Tomato 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 is the text near-black for #398efe: softer than #000 and cool enough to feel like part of the same palette.
Medium Sea Green completes a triad with #398efe — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash.
Tomato completes a triad with #398efe — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash.
Amber is paired with #398efe in 8 real palettes, including Heatwave and Blueprint, as the supporting colour.
10 real palettes, including Unity's brand system and Readymag's brand system put Blue beside #398efe, as the supporting colour.
Designers have shipped Cobalt Blue with #398efe: 7 real palettes, including Blue Mono and Carrefour's brand system, as the lead colour.
Crimson is paired with #398efe in 5 real palettes, including Behance's brand system and WWE's brand system, as the accent.
Dark Orange shows up next to #398efe in 4 real palettes, including Playground and Elastic's brand system, as the lead colour.
| #398efe as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 3.24:1 | fail | pass | fail | |
Aaon black | 6.47:1 | 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 #398efe as the background.
#398efe 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 #398efe and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/398efe-9ca9c4-df5a4e-1f1f2d-e9f0f1?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