Palettes

Ignite UI for Angular exposes CSS variables that allow you to update the colors in your application in a consistent way.

Overview

Ignite UI for Angular exposes over 80 color variants as CSS variables for 8 base colors - primary, secondary, gray, info, success, warn, error, and surface.

The primary, secondary, and gray colors follow the 2014 Material Design Color Palette. This means these colors include the following variants:

All										Primary & Secondary Only
50	100	200	300	400	500	600	700	800	900	A100	A200	A400	A700

As the table above shows, the `gray` color doesn't include the `A100`, `A200`, `A400`, and `A700` variants, while the `primary` and `secondary` colors contain all 14 color variants. We include 5 additional colors that are not part of the 2014 Material Design Color Palette - `info`, `success`, `warn`, `error`, and `surface`.

On top of the aforementioned colors, we also include Level AAA WCAG compliant contrast colors for each color variant. This means that you can safely use the corresponding contrast color variants as foreground colors for the base color variant.

Note

Contrast colors are generated at build-time by the Sass theming engine. Overriding the CSS variables will not update the corresponding contrast colors.

Here's an excerpt of the primary color as declared in the Light Material Palette:

:root {
  --ig-primary-h: 204deg;
  --ig-primary-s: 100%;
  --ig-primary-l: 50%;
  --ig-primary-a: 1;
  --ig-primary-50: hsla(
                      var(--ig-primary-h), 
                      calc(var(--ig-primary-s) * 1.23),
                      calc(var(--ig-primary-l) * 1.78), 
                      var(--ig-primary-a)
                    );
  --ig-primary-100: hsla(
                      var(--ig-primary-h), 
                      calc(var(--ig-primary-s) * 0.8),
                      calc(var(--ig-primary-l) * 1.66),
                      var(--ig-primary-a)
                    );
  --ig-primary-200: hsla(
                      var(--ig-primary-h),
                      calc(var(--ig-primary-s) * 0.64),
                      calc(var(--ig-primary-l) * 1.43),
                      var(--ig-primary-a)
                    );
  // ...
  --ig-primary-50-contrast: black;
  --ig-primary-100-contrast: black;
  --ig-primary-200-contrast: black;
  // ...
}

All primary colors variants are derived from 4 base variables - --ig-primary-h, --ig-primary-s, --ig-primary-l, and --ig-primary-a. Each one of these variables holds the HSLA parts for a single color. HSLA stands for hue, saturation, lightness, and alpha. It's another color scheme used to describe colors. We decided to use this approach as it allows us to modify all variants of the primary, secondary and other colors at runtime.

Defining Palettes

If you wanted to change the color variants for a color from the palette, you can do so by overriding its HSLA values in your stylesheets. For instance, changing the primary colors is as easy as writing:

/* The HSLA representation of orange (#ffa500) */
/* hsla(38.8,100%,50%, 1); */
:root {
  --ig-primary-h: 38.8deg; 
  --ig-primary-s: 100%; 
  --ig-primary-l: 50%; 
  --ig-primary-a: 1; 
}

This will automatically update all the other primary variants.

You will notice that color variants for each color are monochromatic. This is because all color variants are generated from the HSLA variables.

Scoping

We've seen that overriding colors in the palette is relatively easy. We can update the global palette by scoping color variants to the :root selector in the styles.css file of our application:

Let's say your corporate primary color is #9f349c and you want to create primary variants for it. Here's how you would go about doing this. First get the HEX representation of the color in the HSLA color space. In this case it's 302deg for hue, 51% for saturation, 41% for lightness and 1 for alpha. Having derived the HSLA values, all you need to do to update the primary palette to this color is replace the global h, s, and l values for the primary palette:

:root {
  --ig-primary-h: 302deg;
  --ig-primary-s: 51%;
  --ig-primary-l: 41%;
}

This will not automatically calculate the contrast color for each primary color variant. There are many tools out there that will help you determine if a specific color has enough contrast when used in combination with another color. You can use the built-in contrast checker in Chrome when determining the contrast color you want to pick for each color variant. We provide a Sass function for generating color palettes at build-time. If you prefer that we generate all color variants and their contrast colors for you from your own colors, check out the Palettes with Sass section of the documentation.

Apart from having a single global palette, you can also create several palettes scoped to other CSS selectors. For example, we can have a blue and red palette scoped to class selectors:

/* styles.css */

/* cornflowerblue hsl(218.5,79.2%,66.1%) */
.blue-theme {
  --ig-primary-h: 218.5deg; 
  --ig-primary-s: 79.2%; 
  --ig-primary-l: 66.1%; 
  --ig-primary-a: 1; 
}

/* brick red hsl(351.7,57%,52.5%) */
.red-theme {
  --ig-primary-h: 351.7deg; 
  --ig-primary-s: 57%; 
  --ig-primary-l: 52.5%; 
  --ig-primary-a: 1; 
}

<app-component class="blue-theme"></app-component>

Then you can simply overhaul the colors in your application by changing the value of the class attribute from blue-theme to red-theme.

This approach works for overriding palette colors for individual components as well. In some instances, you don't want to create multiple palettes, but you would want to change a palette color used in component.

Let's look at the material avatar component theme. It uses the 400 variant of the gray color for its background. Now, we can customize the theme by overriding the property responsible for setting the background, or we could change the disabled background color for it by overriding the gray 400 palette color:

igx-avatar {
  --ig-gray-400: 146deg, 36%, 64%;
}

Dark vs. Light

Warning

The colors that have the biggest impact on foreground and background colors are gray and surface. These two colors will be displayed against one another in most cases. For that reason the surface color should always contrast the gray.

Palettes in Ignite UI for Angular dictate whether a theme is going to be light or dark. The two colors that have the biggest impact on that are gray and surface. See, the gray color variants in all themes are based on either a very light color shade, like #fff, or a very dark one like #222. Light themes have gray variants based on dark shades of gray, while dark themes are the opposite - all gray variants are a shade of white. These gray colors will be displayed against another color, usually the surface color. The surface color should always be on the opposite end of the gray in the gray scale to ensure themes look good.

To make this a bit clearer, below is a list of some gray and surface color variants in both a light and a dark theme;

Material Light:

:root {
  /* surface is set to white, i.e. ligthness 100% */
  --ig-surface-h: 0deg;
  --ig-surface-s: 0%;
  --ig-surface-l: 100%;
  --ig-surface-a: 1;
  --ig-gray-h: 0deg;

  /* grays are based on black to contrast the surface color */
  --ig-gray-h: 0%;
  --ig-gray-s: 0%;
  --ig-gray-900: var(--ig-gray-h), var(--ig-gray-s), 13%;
}

Material Dark:

:root {
  /* surface is a dark shade of gray, i.e. lightness only at 13% */
  --ig-surface-h: 0deg;
  --ig-surface-s: 0%;
  --ig-surface-l: 13%;
  --ig-surface-a: 1;

  /* grays are based on white to contrast the surface color */
  --ig-gray-h: 0deg;
  --ig-gray-s: 0%;
  --ig-gray-900: var(--ig-gray-h), var(--ig-gray-s), 98%;
}

Be mindful when changing the gray and surface color variants as they are used in most components and have a big impact on their overall look and feel.

Other Colors

So far we've covered the primary, secondary, gray, and surface color variants and how you can override them. There are four more colors - info, success, warn, and error. They are usually used to set the colors in different states. For example, the igx-input-group component uses these colors in its input validation states. They can be changed as the first three variants. Just update their h, s, and l variables.