Palettes / Colors / #1237B3

#1237B3 — Vivid Blue

#1237B3 is a blue color we call Vivid Blue, closest to the named color DarkSlateBlue (#483D8B). It belongs to the blue family.

Color name

Closest CSS keyword: darkslateblue (#483D8B) — not an exact match. CSS darkslateblue gives you #483D8B, a different color; use #1237B3 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.

#1237B3 is a cool blue color associated with trust, calm and professionalism. 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 #B58F12; it also sits naturally between #128AB5 and #3D12B5. In the palettes below you can see it working alongside real color combinations from our collection.

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Color values

RGB & CMYK percentages

Red 7% · Green 22% · Blue 70%

Cyan 90% · Magenta 69% · Yellow 0% · Key 30%

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

Previews

CSS code for #1237B3

.text { color: #1237B3; }
.background { background-color: #1237B3; }
.border { border: 3px solid #1237B3; }
.text-rgb { color: rgb(18, 55, 179); }
.text-hsl { color: hsl(226, 82%, 39%); }
.text-shadow-hex { text-shadow: 4px 4px 2px #1237B3; }
.text-shadow-rgba { text-shadow: 4px 4px 2px rgba(18, 55, 179, 0.8); }
.box-shadow-hex { box-shadow: 1px 1px 3px 2px #1237B3; }
.box-shadow-rgba { box-shadow: 1px 1px 3px 2px rgba(18, 55, 179, 0.8); }

HTML: <p style="color:#1237B3">Text here</p> · <div style="background-color:#1237B3">Div content here</div>

Shades of #1237B3

Tints of #1237B3

Tones of #1237B3

Color harmonies

Complementary — #B58F12:

Analogous:

Triadic:

Contrast & accessibility

Best text color on #1237B3: #FFFFFF.

Semi-transparent (opacity) text on #1237B3

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 #1237B3 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 #1237B3 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

← #1237B2  ·  #1237B4 →

Frequently asked questions

What color is #1237B3?

#1237B3 is Vivid Blue, a blue color (RGB 18, 55, 179). Its closest standard named color is DarkSlateBlue.

What is the RGB and HSL of #1237B3?

#1237B3 is RGB 18, 55, 179 — HSL 226°, 82%, 39% — CMYK 90%, 69%, 0%, 30%.

What colors go with #1237B3?

Its complement is #B58F12; analogous partners are #128AB5 and #3D12B5. It also appears in 6+ palettes in our collection.

Can I use #1237B3 for text?

White text on #1237B3 has a contrast ratio of 9.45:1 (passes WCAG AA); black text gives 2.22:1.