Palettes / Colors / #ECFF40

#ECFF40 — Vivid Yellow

#ECFF40 is a yellow color we call Vivid Yellow, closest to the named color GreenYellow (#ADFF2F). It belongs to the yellow family.

Color name

Closest CSS keyword: greenyellow (#ADFF2F) — not an exact match. CSS greenyellow gives you #ADFF2F, a different color; use #ECFF40 when you need this exact shade.

Sources: common names follow widely used color-name references; CSS keywords and their hex values follow the CSS Color specification.

#ECFF40 is a warm yellow color associated with optimism, attention and cheer. It is saturated enough to be the accent — buttons, highlights and calls to action — while neutrals do the quiet work around it.

Its strongest partner is its complement #5542FF; it also sits naturally between #FFB442 and #8EFF42. In the palettes below you can see it working alongside real color combinations from our collection.

Copy HEX Copy RGB Copy HSL Download PNG swatch SVG

Color values

RGB & CMYK percentages

Red 93% · Green 100% · Blue 25%

Cyan 7% · Magenta 0% · Yellow 75% · Key 0%

CMYK values are unprofiled approximations for screen reference — not a print-proofing guarantee.

Previews

CSS code for #ECFF40

.text { color: #ECFF40; }
.background { background-color: #ECFF40; }
.border { border: 3px solid #ECFF40; }
.text-rgb { color: rgb(236, 255, 64); }
.text-hsl { color: hsl(66, 100%, 63%); }
.text-shadow-hex { text-shadow: 4px 4px 2px #ECFF40; }
.text-shadow-rgba { text-shadow: 4px 4px 2px rgba(236, 255, 64, 0.8); }
.box-shadow-hex { box-shadow: 1px 1px 3px 2px #ECFF40; }
.box-shadow-rgba { box-shadow: 1px 1px 3px 2px rgba(236, 255, 64, 0.8); }

HTML: <p style="color:#ECFF40">Text here</p> · <div style="background-color:#ECFF40">Div content here</div>

Shades of #ECFF40

Tints of #ECFF40

Tones of #ECFF40

Color harmonies

Complementary — #5542FF:

Analogous:

Triadic:

Contrast & accessibility

Best text color on #ECFF40: #000000.

Semi-transparent (opacity) text on #ECFF40

Text set with opacity blends into the background, so its real contrast is lower than the solid ratios above. Choose a text color and an opacity to see the blended color and its true ratio:

How #ECFF40 looks with color blindness

Simulated with standard Machado color-vision-deficiency matrices — useful when this color carries meaning in charts, maps or interfaces:

Closest design-system colors

The nearest matches in the Tailwind CSS, Material Design and Bootstrap palettes — handy when you need a framework class instead of a raw hex:

Palettes with a similar color

These palettes use a close neighbour of #ECFF40 rather than the exact color:

Similar colors

The closest colors that actually appear in our palette collection — click any to open its page:

Browse neighbouring colors

← #ECFF3F  ·  #ECFF41 →

Frequently asked questions

What color is #ECFF40?

#ECFF40 is Vivid Yellow, a yellow color (RGB 236, 255, 64). Its closest standard named color is GreenYellow.

What is the RGB and HSL of #ECFF40?

#ECFF40 is RGB 236, 255, 64 — HSL 66°, 100%, 63% — CMYK 7%, 0%, 75%, 0%.

What colors go with #ECFF40?

Its complement is #5542FF; analogous partners are #FFB442 and #8EFF42. It also appears in 6+ palettes in our collection.

Can I use #ECFF40 for text?

Black text on #ECFF40 has a contrast ratio of 18.94:1 (passes WCAG AA); white text gives 1.11:1.