#3f4551 - Dark Crypt color

A deep, muted slate-blue with cool undertones, appearing as a restrained navy-gray that hints at indigo and charcoal. It feels sophisticated and calm, evoking overcast skies or well-worn denim at dusk. Versatile and modern, it provides a strong neutral base that pairs beautifully with warm metallics, soft pastels, or vibrant ochres for contrast. Ideal for backgrounds, elegant branding, and interiors seeking a serene yet grounded atmosphere without feeling heavy or overly dramatic.

#3f4551 color RGB value is 63, 69, 81, and the CMYK value is 0.222, 0.148, 0.00, 0.682. Alternative names for that color are: dark crypt, gray, darkslategray, mako, outer space, indigo, darkslategrey.

Open Color Palette Builder Open Color Wheel

Color Conversion

Name	Values	CSS
RGB(0-255)	63, 69, 81	rgb(63, 69, 81)
CMYK	0.222, 0.148, 0.00, 0.682	-
sRGB	0.247, 0.271, 0.318	rgb(24.7%, 27.1%, 31.8%)
Adobe® 98 RGB compatible	0.262, 0.277, 0.320	color(a98-rgb, 0.262, 0.277, 0.32)
HCT	262, 11.8, 29.2	color(--hct, 262, 8.11%, 29.2%)
HSL	220, 12.5, 28.2	hsl(220, 12.5%, 28.2%)
HSV	220, 22.2, 31.8	color(--hsv, 220, 22.2%, 31.8%)
HWB	220, 24.7, 68.2	hwb(220, 24.7%, 68.2%)
Lab	29.1, -0.281, -8.10	lab(29.1%, -0.281, -8.1)
P3	0.251, 0.270, 0.313	color(display-p3, 0.251, 0.27, 0.313)
XYZ D50	0.0564, 0.0587, 0.0652	color(xyz-d50, 0.056, 0.059, 0.065)