#66A4B0Seaside (#66A4B0) is a light, muted sky blue with an OKLCH hue of 211°, lightness 0.68 and chroma 0.066. 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 | #66A4B0 |
|---|---|
| RGB | rgb(102, 164, 176) |
| HSL | hsl(190, 32%, 55%) |
| HSV | hsv(190, 42%, 69%) |
| CMYK | cmyk(42%, 7%, 0%, 31%) |
| CIE Lab | lab(63.8 -16.8 -12.5) |
| OKLCH | oklch(0.681 0.066 211) |
Under warm 2700K interior light Seaside shifts subtly: drifts toward blue-green, loses intensity; in north-facing or shaded light it is virtually unchanged. Overall drift across common illuminants is small (max ΔE ≈ 1.9), so it is a lighting-stable choice.
#72a0a5 — ΔE 1.9, shifts subtly: drifts toward blue-green, loses intensity#6ea5ac — ΔE 1.1, shifts subtly: leans toward blue-green#66a4b0 — ΔE 0.0, is virtually unchanged#65a5b2 — ΔE 0.3, is virtually unchangedTest Seaside 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 2.8:1 and against black 7.5:1, 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.
#d9f9ff · #9ed4df · #66a4b0 · #4d8792 · #2d626c · #0b3f48
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.
#95cbbf · #77b9b8 · #66a4b0 · #578fa7 · #537998 · #4f6485
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.
#abb8d0 · #66a4b0 · #4a8590 · #475d89 · #0f4b55 · #1e293e
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.
#c0e6ee · #abbfc3 · #66a4b0 · #9f675c · #3f5e64 · #2b3f43
The anchor as the only color in the room. True neutrals or complement-warmed near-neutrals let it stay dominant.
#f9efed · #66a4b0 · #748083 · #504a49 · #142123 · #020101
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.
#e0f7fb · #b5cfd5 · #66a4b0 · #002c33 · #00080b · #e5553f
The same quiet ground carrying one bright gold voice — the high-energy pairing a cool or muted anchor cannot reach through its own temperature.
#e0f7fb · #b5cfd5 · #66a4b0 · #002c33 · #00080b · #edbd4d
The opposite hue on the perceptual wheel, tempered to field strength — warm/cool tension without vibration.
#ffedea · #66a4b0 · #9e7168 · #6f3b32 · #37100a · #000305
The complement's two neighbours instead of the complement itself — strong contrast with a lower clash risk.
#ffedea · #66a4b0 · #9c6f7b · #69411c · #360f1d · #110400
Three hues spaced evenly around the wheel; the anchor leads and the other two are held at supporting strength.
#fbedf9 · #66a4b0 · #93718e · #5b4a12 · #271d00 · #030003
Two complementary pairs offset by 90° — the richest chord, kept usable by a strict lightness hierarchy.
#f4efff · #66a4b0 · #84769c · #6f3b32 · #1a2200 · #050000
#7CB2BC · #92C0C9 · #A7CED6 · #BDDCE2 · #D2EAEF
#4F8792 · #396B75 · #235159 · #0E373F · #002026
#73A2AB · #7E9FA6 · #889DA1
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.