#04D9FFNeon Blue (#04D9FF) is a light, saturated sky blue with an OKLCH hue of 217°, lightness 0.82 and chroma 0.145. 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 | #04D9FF |
|---|---|
| RGB | rgb(4, 217, 255) |
| HSL | hsl(189, 100%, 51%) |
| HSV | hsv(189, 98%, 100%) |
| CMYK | cmyk(98%, 15%, 0%, 0%) |
| CIE Lab | lab(80.1 -30.7 -30.8) |
| OKLCH | oklch(0.816 0.145 217) |
Under warm 2700K interior light Neon Blue shifts noticeably: leans toward blue-green, loses intensity; in north-facing or shaded light it is virtually unchanged. Overall drift across common illuminants is small (max ΔE ≈ 2.6), so it is a lighting-stable choice.
#4ad5ef — ΔE 2.6, shifts noticeably: leans toward blue-green, loses intensity#34dafa — ΔE 1.2, shifts subtly: leans toward blue-green#04d9ff — ΔE 0.0, is virtually unchanged#00daff — ΔE 0.3, is virtually unchangedTest Neon Blue 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 1.7:1 and against black 12.37:1, so black text is the stronger pairing. That pairing passes WCAG AA for body text. Avoid white text on this color entirely.
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.
#dcf7ff · #04d9ff · #00b5d5 · #008ba5 · #006477 · #003f4c
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.
#7bf5e6 · #49e9f2 · #04d9ff · #41bef6 · #5aa3e6 · #6889d0
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.
#04d9ff · #90a2d2 · #0095af · #4560ba · #005666 · #212f5a
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.
#c7effa · #04d9ff · #de7051 · #176a7c · #004a58 · #002b35
The anchor as the only color in the room. True neutrals or complement-warmed near-neutrals let it stay dominant.
#04d9ff · #b3a29e · #62797f · #4e4340 · #052027 · #030000
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.
#fceeeb · #d5c5c1 · #aa9893 · #321e19 · #0e0100 · #04d9ff
The opposite hue on the perceptual wheel, tempered to field strength — warm/cool tension without vibration.
#dee2bd · #04d9ff · #d67727 · #5a6fa7 · #533339 · #061412
The complement's two neighbours instead of the complement itself — strong contrast with a lower clash risk.
#eadab6 · #04d9ff · #c6a48e · #c35b81 · #4b384d · #041120
Three hues spaced evenly around the wheel; the anchor leads and the other two are held at supporting strength.
#04d9ff · #b99db1 · #9e588d · #534500 · #231c00 · #060004
Two complementary pairs offset by 90° — the richest chord, kept usable by a strict lightness hierarchy.
#04d9ff · #ada0bd · #8661a9 · #7e1f00 · #152100 · #220100
#58DFFF · #7DE4FF · #9BEAFF · #B6EFFF · #CEF4FF
#00B1D1 · #008BA5 · #00677A · #004553 · #00252E
#5DD5F2 · #81D1E6 · #9DCCD9
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.