Colour Schemes

Colour Palette and Contrast

Dark interfaces minimise glare and support readability in varying light conditions.

• Use black or dark colours for backgrounds and layers.
• To minimise glare avoid using pure white (#FFFFFF) for backgrounds, text, or icons.
• Use light greys for text #E6E6E6 to maintain visibility without glare


Define a consistent, restricted palette.

Assign one primary accent colour for all interactive elements (links, buttons, highlights). Do not introduce multiple accent colours.

• Maintain a minimum contrast ratio of 4.5:1 for text and icons.
• Aim for 7:1 contrast for all glance-critical information.
• Verify colour contrast using recognised accessibility testing tools.

Check Colour Contrast

Colour must support readability and recognition, not hinder it. Drivers interact with displays in rapidly changing lighting conditions — daylight glare, reflections, tunnels, and night-time illumination — so all colour use must prioritise legibility, contrast, and universal understanding.

Contrast Ratios

Colour contrast between text (or icons) and their background must meet recognised accessibility standards:

• Minimum contrast ratio: 4.5 : 1 for all body text and icons.
• Recommended contrast ratio: 7 : 1 for glance-critical information (e.g. station name, playback state, current track).
• Verify contrast using a WCAG-compliant contrast checker tool for every text–background and icon–background combination.
• Contrast requirements apply in both day mode and night mode variants.

Use of Colour for Meaning

Colour alone must never be the only way information is conveyed.

• Supplement colour cues (e.g. “active”, “error”, “favourite”) with shape, iconography, or labels.
• Example: use both a colour highlight and a star icon to indicate a favourite station.
• This ensures the interface remains understandable for users with colour vision deficiencies

Consistent Accent Colour

Define one primary accent colour for all interactive elements such as links, buttons, and highlights.

• The accent colour must maintain accessible contrast against both background and text.
• Avoid using multiple accent hues that could confuse or dilute meaning.
• Test accent colour legibility on dark and light variants of the interface.

Colour Temperature and Glare

Avoid using pure white (#FFFFFF) or saturated neon hues as background or accent colours.

• High-luminance colours increase glare and visual fatigue in the confined cabin environment.
• Use light greys (#E6E6E6–#BFBFBF) instead of white, and mid-tone colours for accent work.

Testing for Accessibility

Test colour accessibility under real-world conditions:

• Bright sunlight: confirm text and icons remain readable and do not wash out.
• Low light: ensure sufficient separation between background and interactive elements.
• Colour vision deficiency simulation: check designs using red–green and blue–yellow filters or simulation plugins to confirm information remains perceivable.