Cobalt
#2A51BB · Cobalt
#2A51BB is Cobalt, a cool blue color. It has an RGB value of 42, 81, 187 and a relative luminance of 0.100, making it a dark surface.
Temperature
❄ Cool
Hue family
blue
Luminance
0.10
Conversions
HEX
RGB
HSL
HSV
CMYK
OKLCHPro
Contrast & accessibility
On white
The quick fox
7.02:1
AA normal✓
AA large✓
AAA normal✓
On black
The quick fox
2.99:1
AA normal✕
AA large✕
AAA normal✕
Color harmonies
Complementary
Analogous
Split-complementary
Shades & tints
Similar named colors
Frequently asked
What is the color #2A51BB?
#2A51BB is Cobalt, a cool blue color. In RGB it is 42, 81, 187, and in HSL it is 224°, 63%, 45%.
Is #2A51BB a light or dark color?
#2A51BB has a relative luminance of 0.100, so it reads as a dark surface. Use light text on top of it for the best contrast.
What colors go well with #2A51BB?
Its complementary color is #BB942A. For softer combinations, try the analogous or split-complementary harmonies shown above.