Cathode Green
#00ff55
A green that is about as vivid as sRGB can show at this lightness. It is very light — it works as a page background, not as text.
Hex
#00ff55
RGB
0, 255, 85
OKLCh
87.0% 0.266 145.9°
CIELAB (D50)
88.1, -76.3, 63.2
What is true of this colour, and of no other
- One other named colour sits within ΔE00 2 of it.
- It sits exactly on the sRGB boundary: at this lightness and hue the gamut has nothing left, and a wider display would show a more colourful version of it.
- As text on white it measures APCA Lc 16.7; on black, Lc -86.9. The sign is the polarity, which the WCAG ratio discards.
- Built into an eleven-step scale, 10 of the 10 adjacent pairs stay ΔE00 2 apart — see the ramp.
- protanopia and deuteranopia and tritanopia shift it by ΔE00 24.8 and 24.0 and 51.8 — no red cone.
Text on this colour
White text
1.36:1 — fails AA
Black text
15.44:1 — passes AA
Black text is the better of the two at15.44:1. That is enough for body text.
As text on white, it needs to change
#008a2a is the nearest colour of the same hue that passes AA on white, at 4.50:1. Only the lightness moved, and some saturation was given up to stay inside sRGB.
The same colour, with one cone missing
As you see it
#00ff55
protanopia
#f2f253 · ΔE00 24.8
deuteranopia
#dbdb5e · ΔE00 24.0
tritanopia
#bdbdff · ΔE00 51.8
The twelve nearest named colours
Ranked by CIEDE2000 — perceptual distance, not hex arithmetic. The closest isBright Light Green at ΔE00 0.717: below 1.0 — an ordinary observer cannot tell these apart, even side by side. What the numbers mean.
- Bright Light GreenΔE00 0.717 · #2dfe54
- Goblin WarbossΔE00 2.002 · #4efd54
- Green KatamariΔE00 2.008 · #53fe5c
- Puyo Blob GreenΔE00 2.354 · #55ff55
- Lucent LimeΔE00 2.605 · #00ff33
- Radiant HulkΔE00 3.033 · #10f144
- Screamin’ GreenΔE00 3.037 · #66ff66
- Cyber Neon GreenΔE00 3.278 · #00ff26
- Electric Laser LimeΔE00 3.366 · #26ff2a
- Hot GreenΔE00 3.401 · #25ff29
- BiopunkΔE00 3.438 · #66ff55
- AcidΔE00 3.448 · #00ff22
7 of these have no page of their own: pages exist for the 4,961 colours the dataset marks as good names.