README

o-colors

A component to manage colours. Includes the FT colour palette.

Usage
Markup
CSS Custom Properties
Sass
Migration
Contact
Licence

Usage

Check out how to include Origami components in your project to get started with o-colors.

Markup

Colour Usecase Classes

A limited number of colour usecases are available as CSS classes, including:

.o-colors-page-background
.o-colors-box-background
.o-colors-body-text
.o-colors-muted-text

<body class="o-colors-page-background">
    <!-- default background colour set -->
    <!-- e.g. for the core brand `background: #fff1e5;` -->
</body>

More colours are available for build service users as CSS Custom Properties.

CSS Custom Properties

Colour Palette Custom Properties

All palette colors, including default mixes and tones, are available as CSS Custom Properties (CSS Variables) in the format --o-colors-[NAME].

See all palette colours available in the registry.

.ft-pink {
    background: var(--o-colors-paper);
    color: var(--o-colors-black-80);
}

Colour Usecase Custom Properties

A limited number of colour usecases are also available as CSS Custom Properties (CSS Variables), including:

--o-colors-page-background
--o-colors-box-background
--o-colors-body-text
--o-colors-muted-text
--o-colors-link-text
--o-colors-link-hover-text

body {
    background: var(--o-colors-page-background);
}

Sass

o-colors has a number of mixins and functions for you to access the color palette in your project. We recommend Sass projects use these mixins and functions directly. E.g. oColorsByName and oColorsByUsecase. However, it is also possible to output all o-colors CSS Custom Properties (CSS Variables) and classes using the oColors mixin.

@import '@financial-times/o-colors/main';
@include oColors($opts: (
    'palette-custom-properties': true, // e.g. --o-colors-paper
    'usecase-custom-properties': true, // e.g. --o-colors-page-background
    'usecase-classes': true // e.g. .o-colors-page-background
));

Palette Colours

o-colors defines a colour palette (a set of named colours) which may be previewed in the registry. Custom palette colours may be added to the palette to share them with dependencies.

Color Name	Brand Support
black	core, internal, whitelabel
white	core, internal, whitelabel
oxford	core, internal
teal	core, internal
slate	core, internal,
lemon	core, internal,
jade	core, internal
mandarin	core, internal
crimson	core, internal
paper	core
claret	core
wheat	core
sky	core
velvet	core
candy	core
wasabi	core
light-blue	core
graphics-dark-blue	core
ft-pink (previously brand-ft-pink)	core
ft-grey	core
org-b2c	core
org-b2c-dark	core
org-b2c-light	core

There are additional colours in the palette by default including tones and mixes. See the registry demos for a full list.

ft-pink and ft-grey are brand colours which are used in some digital assets, such as the FT logo, but have a limited number of valid use-cases for digital UI. Instead consider paper and slate or a black/paper mix such as black-80. As an example of a usecase for ft-pink, it could be used to prevent a flash of the wrong colour as a logo image loads.

Default Palette Colours

Get a default colour from the palette using oColorsByName.

.example {
    // Get a default o-colors palette colour.
    background: oColorsByName('paper');
}

Custom Palette Colours

To set a custom palette colour to share with other components call oColorsSetColor. Colour names must be namespaced for the project or component using a forward slash.

// Set a custom palette colour within a project `o-example`.
@include oColorsSetColor(
    $color-name: 'o-example/myhotpink',
    $color-value: #ff69b4
);

.example {
    // Get a custom palette colour from a project `o-example`.
    background: oColorsByName('o-example/myhotpink');
}

By default custom colours do not allow tones to reduce the number of colours used within a project. To allow tones set the allow-tones option.

// Set a custom palette colour within a project `o-example`,
// which allows tones of the same colour.
@include oColorsSetColor(
    $color-name: 'o-example/myhotpink',
    $color-value: #ff69b4,
    $opts: ('allow-tones': true)
);

.example {
    // Get a toned custom palette colour from a project `o-example`.
    background-color: oColorsGetTone('o-example/myhotpink', 80);
}

Removing a colour is considered a breaking change and requires a major release. To inform users a colour should not be used deprecate it by passing an $opts argument with a deprecation message.

// Deprecate a custom colour, which will be removed in a future major release.
@include oColorsSetColor(
    $color-name: 'o-example/myhotpink',
    $color-value #ff69b4,
    $opts: ('deprecated': 'Use the default colour claret instead.')
);

See o-colors SassDoc for more details and examples.

Usecases

A colour palette helps products use the same set of colours, but does not help them use the colours consistently. Therefore o-colors provides tools to return colours based on usecases. E.g. a colour for the page background or body text.

Usecase	Property	Brand Support
page	background	core, internal, whitelabel
focus	outline	core, internal
box	background	core, internal
link	text	core, internal
link-hover	text	core, internal
link-title	text	core, internal
link-title-hover	text	core, internal
title	text	core, internal
body	text	core, internal
muted	text	core, internal
tag-link	text	core
tag-link-hover	text	core
opinion-tag-link	text	core
opinion-tag-link-hover	text	core
opinion	background	core
hero	background	core
hero-opinion	background	core
hero-highlight	background	core
Section colors
section-life-arts	all	core
section-life-arts-alt	all	core
section-magazine	all	core
section-magazine-alt	all	core
section-house-home	all	core
section-house-home-alt	all	core
section-money	all	core
section-money-alt	all	core

Default Usecases

To get a colour for a default usecase call oColorsByUsecase.

    html {
        // get the background colour for the page usecase
        background: oColorsByUsecase('page', 'background');
    }

    .paragraph {
        // get the text colour for the body usecase
        color: oColorsByUsecase('body', 'text');
    }

Custom Usecase

To create a new usecase call oColorsSetUseCase.

$usecase: The name of the usecase, e.g. 'page'. This must include a namespace for your component or project followed by a forward slash.
$colors: A map of properties ('text', 'background', 'border', or 'outline') to a palette color name.
$opts (optional):
- deprecated: A deprecation message for the usecase.

    // set colours for a "stripes" in o-example.
    @include oColorsSetUseCase('o-example/stripes', (
        'text': 'white',
        'background': 'black',
        'border': 'black-50'
    ));

Removing a usecase is a breaking change and requires a major release. To inform users a usecase should not be used it should be deprecated. Deprecate a usecase by passing an $opts argument with a deprecation message.

Deprecate all usecase properties:

    // deprecate all usecase properties for the o-example custom usecase "stripes".
    @include oColorsSetUseCase('o-example', 'stripes', (
        'text': 'white',
        'background': 'black',
        'border': 'black-50'
    ), ('deprecated': 'o-example has no stripes anymore, use a different colour'));

Deprecate individual usecase properties:

    // deprecate only the background property for the o-example custom usecase "stripes".
    @include oColorsSetUseCase('o-example', 'stripes', (
        'text': 'white',
        'background': 'black',
        'border': 'black-50'
    ), ('deprecated': ('background': 'o-example stripes has no background anymore, use a different colour')));

Generated Text Colors

oColorsGetTextColor will return a light or dark text color based on the background and an opacity specified.

.example {
    background: oColorsByName('teal');
    // Get a text colour for a teal background
    color: oColorsGetTextColor('teal');
}

.example {
    background: oColorsByName('teal');
    // Get a text colour for a teal background,
    // with greater than usual opacity (80)
    color: oColorsGetTextColor('teal', 80);
}

The contrast of the background and resulting text colour is checked against WCAG 2.1 guidelines. If the contrast is too low an error is thrown. By default the contrast is checked for normal text at AA level. The contrast may be checked for large text or against stricter AAA recommendations (aa-normal, aa-large, aaa-normal, or aaa-large).

.example-large-text {
    background: oColorsByName('teal');
    // Get a text colour for a teal background,
    // enforce a lower level of contrast "large text".
    color: oColorsGetTextColor('teal', $minimum-contrast: 'aa-large');
}

Set $minimum-contrast to null to remove contrast checking. Only ignore contrast for incidental or logo text, otherwise your project may be inaccessible.

Mix colors

oColorsMix will mix two colors based on a percentage. This gives the impression of the base color appearing at the percentage opacity over the background color. oColorsMix will accept either a color value or the name of an o-colors palette color as arguments.

By default oColorsMix mixes with the page background colour usecase:

$color: oColorsMix($color: 'black', $percentage: 30); // same as black-30

But two colours may be given. For example to mix claret over slate at 20%:

$color: oColorsMix($color: 'claret', $background: 'slate', $percentage: 20);

Tone Palette Colors

An o-colors tone is a palette colour with modified saturation and luminosity, to create a lighter or darker colour whilst retaining vibrancy.

Recommended tones are already in the colour palette, e.g. teal-80 (see default tones in the registry). However for cases where a new tone is required use oColorsGetTone. It will return a new color based on a specified brightness.

.teal-tone-example {
    background-color: oColorsGetTone('teal', 80);
}

For design consistency not all colours are allowed to be toned. Only colours with default tones in the palette (e.g. teal, oxford, and claret) may be used. Other colours may still be mixed. If your project has defined custom colours using oColorsSetColor, these may be toned by setting the allow-tones option.

Colour Tools

o-colors provides other useful functions for working with colours, including:

oColorsGetContrastRatio
oColorsColorBrightness
oColorsColorLuminance