#309CD0Blue Burst (#309CD0) is a mid-tone, soft sky blue with an OKLCH hue of 234°, lightness 0.66 and chroma 0.122. It sits on the cool side of the color wheel. In practice it behaves as a mid-weight working color for secondary surfaces and editorial blocks.
| HEX | #309CD0 |
|---|---|
| RGB | rgb(48, 156, 208) |
| HSL | hsl(200, 63%, 50%) |
| HSV | hsv(200, 77%, 82%) |
| CMYK | cmyk(77%, 25%, 0%, 18%) |
| CIE Lab | lab(60.7 -12.6 -35.2) |
| OKLCH | oklch(0.656 0.122 234) |
Under warm 2700K interior light Blue Burst shifts subtly: loses intensity; in north-facing or shaded light it is virtually unchanged. Overall drift across common illuminants is small (max ΔE ≈ 2.2), so it is a lighting-stable choice.
#4799c3 — ΔE 2.2, shifts subtly: loses intensity#3e9dcc — ΔE 1.1, shifts only faintly, with no single dominant change#309cd0 — ΔE 0.0, is virtually unchanged#2d9dd3 — ΔE 0.5, is virtually unchangedTest Blue Burst in the color lighting simulator — sweep it through daylight, warm 2700K light, 4000K LED, and shade alongside the rest of your palette.
Against white it measures 3.09:1 and against black 6.79:1, so black text is the stronger pairing. That pairing passes WCAG AA for body text.
One color explored: close hues with real lightness and chroma structure, so the palette is the anchor through value rather than a set of colors.
#d3eeff · #79cdfb · #309cd0 · #0e7faf · #005a7e · #00374f
The anchor's neighbours on the wheel — everything shares an undertone, so the chord carries color without anything having to be muted to get along.
#63c8d0 · #42b3d1 · #309cd0 · #4683c0 · #516baa · #555490
The mid-gap pairing — sage and mustard, terracotta and olive. A foil rotated 40–65° toward warm or cool: too far to be kin, too near to argue, carried by temperature and a deliberate value offset.
#acabd5 · #309cd0 · #247ca7 · #534996 · #00425e · #211d41
One deliberately opposed voice — a single restrained counterpoint across the wheel, or temperature against temperature where the anchor is too muted to carry a loud opposite.
#abdefc · #9db7c7 · #309cd0 · #a55a1d · #2c576e · #1d3847
The anchor as the only color in the room. True neutrals or complement-warmed near-neutrals let it stay dominant.
#fcefe7 · #309cd0 · #697983 · #4d4540 · #0e1f28 · #030100
This color as a ground rather than a subject — its own restraint held across a narrow value band, carrying one saturated voice from the opposite temperature.
#fbefe8 · #d6c9c1 · #ae9f96 · #3d2c20 · #1b0a02 · #309cd0
The opposite hue on the perceptual wheel, tempered to field strength — warm/cool tension without vibration.
#d6d9b4 · #9da7cc · #309cd0 · #a82b15 · #573747 · #01092f
The complement's two neighbours instead of the complement itself — strong contrast with a lower clash risk.
#ffeee3 · #309cd0 · #a85e59 · #5b4200 · #3f0003 · #0e0600
Three hues spaced evenly around the wheel; the anchor leads and the other two are held at supporting strength.
#ffecf3 · #309cd0 · #a35d7a · #464c00 · #1c1f00 · #0f0004
Two complementary pairs offset by 90° — the richest chord, kept usable by a strict lightness hierarchy.
#feeaff · #309cd0 · #936196 · #6f3500 · #002502 · #1d0700
#55ACDA · #73BBE4 · #8FCBED · #ABDAF7 · #C6EAFF
#1880AF · #00668E · #004C6C · #00344B · #001D2D
#4F9AC3 · #6598B6 · #7796A8
Its moderate chroma lets it work in mid-size areas — upholstery, secondary UI surfaces, editorial blocks — without overwhelming neighbors. In palettes it pairs most predictably with its tonal ramp and analogous neighbors; reserve the complementary hue for small, deliberate contrast.