Find the color opposite the color you pass in on the color wheel.

E.g., if you pass in a reddish color, you should expect to get back a tealish color.

Find the other two colors in the triadic scheme defined by the color passed in.

Triadic color schemes are evenly-spaced, so each of the three colors is 120 degrees from the others.

The internet says this scheme will be vibrant, and that you should mostly use one of the three colors and only use the other two for accents.

Build a three-color scheme by rotating the same amount from the initial color in both directions.

triadic, the evenly-spaced 3-color scheme, can be defined in terms of this function:

triadic color =
    splitComplementary 120 color

Initial rotation is clamped between 0 and 180.

Find four equally-spaced colors along the color wheel starting from the passed-in color.

Find four colors along the color wheel starting from the passed-in color.

This differs from the square helper in that our values aren't equally spaced -- we are selecting colors on the color wheel with a rectangle. We can actually define square in terms of this function as follows:

square color =
    tetratic 60 color

We'll rotate the number of degrees passed in along the color wheel to find our first color. Then we'll rotate the "length" of the rectangle -- as much as we need to in order to make it all the way around.

Initial rotation is clamped between 0 and 180.

Create a monochromatic palette. The Float argument is size of the Lightness steps that you'd like in the palette.

If you wanted a grayscale palette, and you wanted it to have five colors, you could do something like this:

grayscalePalette =
    monochromatic 20 black

Colors will be arranged from darkest to lightest.

Find a high contrast color to use in concert with the passed-in color. This funciton will return either black or white, whichever will be higher contrast given the starter color.

This is most useful when working with styleguide colors. It will not produce particularly visually pleasing results, but they will be consistent and readable.

Use this function to produce a new shade of the Color. Note: shades will be darker than the starting color. If you want a lighter color, please see tint.

Pass in the percentage value by which you want to darken the color.

Use this function to produce a new tint of the Color. Note: tints will be lighter than the starting color. If you want a darker color, please see shade.

Pass in the percentage value by which you want to lighten the color.

Use this function to produce a new tone of the Color.

Essentially this means adding grays to the color you pass in. It's implemented, though, by adjusting the saturation of the color. You can pass in a positive or negative percentage value.

Convert the color you pass in to a grayscale version. Essentially this uses the luminance of the color you pass in to make a corresponding white <-> black value.

Use this function to invert a color. E.g., black inverted is white, white inverted is black....

Rotate a color by degrees [0, 360).

Picture the color wheel. Suppose you want to find 8 evenly-spaced colors from a starting color. You might do something like this:

import Color
import Color.Generator


eightEvenColors : Color -> List Color
eightEvenColors color =
    List.range 0 7
        |> List.map (\i -> Color.Generator.rotate (toFloat i * 360 / 8) color)

Check out this code on Ellie here: https://ellie-app.com/3CRfDs2HLvGa1.

Modify the saturation of a color (see notes on HSL color space).

Modify the lightness of a color (see notes on HSL color space).