# Chameleon
[](https://semaphoreci.com/supersimple/chameleon)
Chameleon is a utility that converts colors from one model to another.
It currently supports: Hex, RGB, CMYK, HSL, HSV, Pantone, and Keywords.
## Use
Chameleon represents colors using Elixir structs. Create a color using one
of the provided structs:
```elixir
iex> mycolor = Chameleon.RGB.new(255, 0, 0)
%Chameleon.RGB{b: 0, g: 0, r: 255}
```
Once you have a color, Chameleon can convert that color to another colorspace or
format:
```elixir
iex> Chameleon.convert(mycolor, Chameleon.HSV)
%Chameleon.HSV{h: 0, s: 100, v: 100}
iex> Chameleon.convert(mycolor, Chameleon.Hex)
%Chameleon.Hex{hex: "FF0000"}
```
Chameleon can also convert strings:
```elixir
iex> Chameleon.convert("#ff0000", Chameleon.RGB)
%Chameleon.RGB{b: 0, g: 0, r: 255}
iex> Chameleon.convert("red", Chameleon.CMYK)
%Chameleon.CMYK{c: 0, k: 0, m: 100, y: 100}
```
If Chameleon doesn't know how to convert the color, you'll get an error:
```elixir
iex> Chameleon.convert("#112233", Chameleon.Pantone)
{:error, "No pantone match could be found for that color value."}
```
## Adding color types
Chameleon uses Elixir protocols internally to perform the conversions. This
makes it possible to add support for new colorspaces and formats in your own
code. To do this, first create a struct for your color:
```elixir
defmodule MyApp.FancyColor do
@enforce_keys [:c1, :c2, :c3]
defstruct @enforce_keys
def new(c1, c2, c3), do: %__MODULE__{c1: c1, c2: c2, c3: c3}
end
```
Next, create modules for converting the color between types. Module names must
be of the form `FromColor.ToColor`. For example:
```elixir
defmodule MyApp.FancyColor.Chameleon.RGB do
defstruct [:from]
defimpl Chameleon.Color do
def convert(%{from: fancy}) do
# Do math here...
Chameleon.RGB.new(fancy.c1, fancy.c2, fancy.c3)
end
end
end
```
It is recommended to add conversion modules to and from RGB. When Chameleon
doesn't find a direct conversion from one color to another, it will attempt to
convert through RGB. By supporting RGB conversions, your color type will be
convertable between many color types. Of course, color conversion is frequently
a lossy operation and you may want to implement more conversion modules.
## Caveat(s)
Pantone is designed to be used on printed work only. As such, it is disingenuous to say a
pantone value can be translated to a hex value since hex values will look different depending
on the device displaying them. However, if you have a pantone value and want to find a
device-displayable analog, this library will work.
## Installation
The package can be installed by adding `chameleon` to your list of dependencies in `mix.exs`:
```elixir
def deps do
[
{:chameleon, "~> 2.0.0"}
]
end
```
## Contribution
Contributions are welcomed. Please open a pull request or file an issue with your ideas.
Some ideas would be:
* Add a new color model for conversion
* Add functionality to generate complementary colors
* Handle errors for invalid input values
