adjustcolor
Alter a color specification

### Description

Transforms colors to related colors.

### Usage

    adjustcolor(col, alpha.f = 1, red.f = 1, green.f = 1, blue.f = 1,
    offset = c(0, 0, 0, 0), transform = diag(c(red.f, green.f, blue.f,
    alpha.f)))

### Arguments

col | a vector of color strings or indices acceptable to col2rdb.
alpha.f | the factor by which to change the alpha (opacity) component of the color.
red.f | the factor by which to change the red component of the color.
green.f | the factor by which to change the green component of the color.
blue.f | the factor by which to change the blue component of the color.
offset | a vector of numbers in the range -1 to +1 giving an additive change to the four color components. Negative one (-1) sets the color component to zero. Positive 1 (+1) increases the color component to its maximum value, 255. Its length must be a multiple of 4.
transform | a 4 by 4 matrix used to multiply the input red-green-blue-alpha values. By default, transform is constructed from the red.f, green.f, blue.f, and alpha.f values so each is changed independently of the others.

Value
returns a vector of color strings in the format "#RRGGBBAA", giving the 2-digit hexadecimal values for the red, green, blue, and alpha (opacity) components of the modified colors.
See Also
col2rgb, colorRamp.
Examples

    adjustcolor(c("red", "orange", "#004040a0"), alpha.f = 0.25) # make translucent colors

Package grDevices version 6.1.5-18
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