HWB (Hue, Whiteness, Blackness) is a
cylindrical-coordinate representation of points in an
RGB color model, similar to
HSL and HSV
HSL (for hue, saturation, lightness) and HSV (for hue, saturation, value; also known as HSB, for hue, saturation, brightness) are alternative representations of the RGB color model, designed in the 1970s by computer graphics researchers to more ...
. It was developed by
HSV’s creator
Alvy Ray Smith
Alvy Ray Smith III (born September 8, 1943) is an American computer scientist who co-founded Lucasfilm's Computer Division and Pixar, participating in the 1980s and 1990s expansion of computer animation into feature film.
Education
In 1965 ...
in 1996 to address some of the issues with HSV. HWB was designed to be more intuitive for humans to use
and slightly faster to compute. The first coordinate, H (
Hue
In color theory, hue is one of the main properties (called color appearance parameters) of a color, defined technically in the CIECAM02 model as "the degree to which a stimulus can be described as similar to or different from stimuli that ...
), is the same as the Hue coordinate in
HSL and HSV
HSL (for hue, saturation, lightness) and HSV (for hue, saturation, value; also known as HSB, for hue, saturation, brightness) are alternative representations of the RGB color model, designed in the 1970s by computer graphics researchers to more ...
. W and B stand for Whiteness and Blackness respectively and range from 0–100% (or 0–1). The mental model is that the user can pick a main hue and then “mix” it with white and/or black to produce the desired color.
[ This is the original paper describing the HWB color model.]
HWB was included in the
CSS
Cascading Style Sheets (CSS) is a style sheet language used for describing the presentation of a document written in a markup language such as HTML or XML (including XML dialects such as SVG, MathML or XHTML). CSS is a cornerstone t ...
Level 4 Color Module in 2014.
Conversion
HWB is very closely related to
HSV, and therefore the conversion formulas are fairly simple.
Before conversion from HWB, if the sum of whiteness and blackness exceeds 100%, both components must be scaled back proportionally to make the sum 100%.
Swatches
The ''CSS Color Level 4'' draft specification
includes a number of HWB example color swatches.
[CSS Color Module Level 4]
/ref>
References
Color space
{{Color-stub