Accent Colors

Flutter, Google’s popular UI toolkit for building natively compiled applications for mobile, web, and desktop, has revolutionized the way developers design applications. One of the most important aspects of app design is color. Colors not only make an app visually appealing but also guide users’ attention and enhance usability. Among the various color-related concepts in Flutter, accent colors play a pivotal role. Accent colors are used to highlight key interactive elements, such as buttons, switches, sliders, and other widgets. This post explores accent colors in Flutter in-depth, how to implement them using ThemeData, and best practices for designing apps with vibrant, accessible color schemes.

What is an Accent Color?

In user interface design, an accent color is a secondary color used to emphasize elements and draw users’ attention. While the primary color defines the general brand and look of the app, accent colors are applied to interactive elements and notifications to make them stand out.

In Flutter, accent colors are part of the ColorScheme in the app’s theme. They typically appear on:

Buttons
Floating action buttons
Sliders
Switches
Checkbox and radio buttons
Links or highlighted text

For example, if you set the accent color to orange, buttons or switches that use the secondary color will appear in orange, ensuring consistency throughout the app.

Why Accent Colors Matter

Accent colors are more than just visual decoration—they impact usability, accessibility, and user experience:

Highlight Key Actions: Accent colors guide the user’s eyes toward important actions like submitting a form or toggling a switch.
Improve Accessibility: Properly chosen accent colors can improve contrast and make the app usable for people with visual impairments.
Enhance Brand Identity: Accent colors can reinforce brand colors while maintaining visual harmony with primary colors.
Increase Visual Hierarchy: By differentiating interactive elements from non-interactive ones, accent colors help users navigate the interface intuitively.

Setting Accent Colors in Flutter

Flutter allows developers to define accent colors using the ThemeData class, particularly through the ColorScheme. A simple way to set an accent color is:

ThemeData(
  colorScheme: ColorScheme.fromSwatch().copyWith(secondary: Colors.orange),
)

Here’s a breakdown of this code:

ColorScheme.fromSwatch(): Generates a color scheme based on a primary swatch. The swatch is a Material color palette.
.copyWith(secondary: Colors.orange): Overrides the secondary color in the scheme, which serves as the accent color.
ThemeData(colorScheme: ...): Applies the color scheme to the app’s theme.

By doing this, all widgets that rely on the accent color, such as FloatingActionButton or Switch, will automatically adopt the new color.

Accent Color Examples

Buttons

Flutter buttons, such as ElevatedButton, TextButton, and OutlinedButton, often use the accent color for their active state or highlights.

ElevatedButton(
  onPressed: () {},
  child: Text('Accent Button'),
  style: ElevatedButton.styleFrom(
primary: Theme.of(context).colorScheme.secondary,  ),
)

In this example, the button uses the secondary (accent) color defined in the app’s theme. If the accent color is orange, the button will display in orange.

Floating Action Button

The FloatingActionButton (FAB) is one of the most common elements in Flutter that adopts the accent color:

FloatingActionButton(
  onPressed: () {},
  child: Icon(Icons.add),
  backgroundColor: Theme.of(context).colorScheme.secondary,
)

Switches and Sliders

Widgets like Switch and Slider automatically pick up the accent color from the theme:

Switch(
  value: isSwitched,
  onChanged: (value) {
setState(() {
  isSwitched = value;
});  },
  activeColor: Theme.of(context).colorScheme.secondary,
)

Similarly, sliders can be themed using the accent color:

Slider(
  value: sliderValue,
  onChanged: (newValue) {
setState(() {
  sliderValue = newValue;
});  },
  activeColor: Theme.of(context).colorScheme.secondary,
)

Customizing the Accent Color

While using Colors.orange is straightforward, Flutter also allows you to define custom colors using the Color class:

ThemeData(
  colorScheme: ColorScheme.fromSwatch().copyWith(
secondary: Color(0xFFFFA500), // Custom orange color  ),
)

This is particularly useful for aligning your app’s accent color with a specific brand palette.

Accent Colors with Dark Theme

Flutter supports both light and dark themes. You can define accent colors separately for each theme to ensure visibility and aesthetic consistency:

ThemeData.light().copyWith(
  colorScheme: ColorScheme.light(secondary: Colors.orange),
);

ThemeData.dark().copyWith(
  colorScheme: ColorScheme.dark(secondary: Colors.deepOrange),
);

This ensures that the accent color is visible and accessible in both light and dark modes.

Best Practices for Using Accent Colors

Use Sparingly: Accent colors should highlight specific interactive elements, not dominate the UI.
Maintain Contrast: Ensure the accent color contrasts well with background colors for readability and accessibility.
Consistency Across Widgets: Use the same accent color across all buttons, switches, sliders, and floating action buttons to maintain a consistent design.
Follow Brand Guidelines: Align the accent color with your brand’s visual identity.
Test for Color Blindness: Use online tools to ensure that accent colors are distinguishable for users with color vision deficiencies.

Flutter Widgets that Use Accent Colors

Several widgets in Flutter use the accent color by default or can be customized to do so:

FloatingActionButton
ElevatedButton, TextButton, OutlinedButton
Slider
Switch
Checkbox
Radio
Chip
InputDecoration highlights for TextField

Using the theme’s accent color ensures that all these widgets follow a consistent design language without requiring manual styling for each widget.

Advanced Accent Color Theming

You can define a complete ColorScheme for your app, which includes primary, secondary, surface, background, error, and on-colors. Here’s an example:

final ThemeData theme = ThemeData(
  colorScheme: ColorScheme(
primary: Colors.blue,
primaryContainer: Colors.blue&#91;700]!,
secondary: Colors.orange,
secondaryContainer: Colors.orange&#91;700]!,
surface: Colors.white,
background: Colors.grey&#91;200]!,
error: Colors.red,
onPrimary: Colors.white,
onSecondary: Colors.white,
onSurface: Colors.black,
onBackground: Colors.black,
onError: Colors.white,
brightness: Brightness.light,  ),
);

This approach provides fine-grained control over every color in the app while keeping accent colors consistent.

Material You and Dynamic Accent Colors

Flutter’s support for Material You allows accent colors to dynamically adapt to the user’s wallpaper or system theme on Android. This means your app can automatically adopt system accent colors without hardcoding them:

colorScheme: ColorScheme.fromSeed(seedColor: Colors.orange),

This generates a full color palette based on a seed color, including primary and secondary (accent) colors.

Tips for Testing Accent Colors

Check Across Devices: Colors may appear differently on different screens, so testing is essential.
Simulate Color Blindness: Use emulators or accessibility tools to simulate how users with color blindness will see your accent colors.
Contrast Testing: Use online contrast checkers to ensure your accent colors meet WCAG accessibility standards.
Consistency in Interaction States: Make sure hover, pressed, and disabled states of buttons and interactive elements still respect the accent color.

Common Mistakes with Accent Colors

Overuse: Using the accent color too much dilutes its purpose and reduces visual hierarchy.
Low Contrast: Choosing accent colors that do not contrast with the background can make elements invisible.
Ignoring Dark Mode: Accent colors that look good in light mode may fail in dark mode, causing poor visibility.
Inconsistent Application: Not applying the accent color uniformly to all widgets can result in a fragmented UI experience.