The value passed to the Color constructor, unchanged: a color name or hexadecimal code, a cellstring array of them, an RGB or RGBA matrix, or a cell array of color space names and values.

Color: obj = Color (value)

When value is character vector, it can define a single color either by using one of the acceptable color names given below or by using hexadecimal string values in the forms #FFFFFF and #FFFFFFFF. The former defines an RGB color space, whereas the later defines an RGBA color space that includes transparency.

Valid color names are:

• beige
• black
• blue, lightblue, darkblue
• brown
• coral, lightcoral
• cyan, darkcyan
• green, lightgreen, darkgreen
• gray, grey, lightgray, lightgrey, darkgray, darkgrey
• magenta, darkmagenta
• pink
• red, darkred
• white
• yellow, lightyellow

If you want to apply multiple colors to a given dataset, then you can use a cellstring array whose elements follow the requirements for character vector values described above. The cellstring array must be a vector and its elements can interchangeably contain known color names or hexadecimal color values.

If value is a numeric, it follows Octave’s native RGB tripplet syntax. An RGB triplet is a 1x3 vector where each value is between 0 and 1 inclusive. The first value represents the percentage of Red, the second value the percentage of Green, and the third value the percentage of Blue. This syntax is also extended to support RGBA quadruplets, in which case the fourth value (also between 0 and 1 inclusive) of the 1x4 vector represents the transparency. If you want to apply multiple colors to a given dataset, then you can pass a numeric matrix of Nx3 or Nx4 size with each row representing a distinct RGB tripplet or RGBA quadruplet, respectively.

Alternatively you can define value as a cell array with two elements or an Nx2 cell matrix in case you need to specify multiple colors in the same dataset. The first element of each row represents a color space name, which can be any of the four available choices: rgb, rgba, hsl, and hsla. The second element of each row must be a numeric 1x3 vector for rgb and hsl color spaces, or a numeric 1x4 vector for rgba and hsla color spaces. When assigning color value(s) as a cell array, the RGB values must be between 0 and 255 inclusive, the hue value must be between 0 and 360 inclusive, the saturation and lightness values must be percentages between 0 and 100 inclusive, whereas the alpha value must be between 0 and 1 inclusive. All numeric values except for the transparency are expected to be integer values, otherwise they are rounded to the nearest integer.

Color: json = jsonstring (obj)

jsonstring (obj) returns a character vector, json, holding the color in JSON: a string for a single color and an array of strings for a list of colors, even a list of one.

See also: Color, Fill