Can Everyone See the Story in the Data?
Designing a more accessible experience for complex, data-heavy contact center applications.
Role: UX Lead ⚬ Domain: Contact Center ⚬ Platform: Web ⚬ Focus: Data Visualization
Context
When information is complex, accessibility can't be an afterthought.
Contact-center applications bring together large amounts of information to help users understand situations, make decisions, and complete tasks efficiently. With data-heavy dashboards and complex visualisations, the experience needs to remain clear and usable regardless of how users perceive, navigate, or interact with the information.
The platform supported two major public-sector clients, DWP and HMRC, with users including many older adults. Across the experience, users interacted with dashboards, charts, and workflows where accessibility could directly affect their ability to understand information and complete tasks.
In such an environment, accessibility cannot be treated as a final compliance check. A colour that is difficult to distinguish, a focus state that is easy to miss, a screen-reader announcement that doesn't communicate the right information, or a layout that breaks when enlarged can turn a simple task into a barrier. The goal was to identify these barriers early, understand their impact, and make accessibility part of the experience - not something added at the end.
Challenge
Good colour contrast makes data easier for everyone to see, understand, and interpret.
Data-heavy dashboards often use multiple colours to differentiate information, but subtle colour differences can make charts difficult to interpret - especially for users with low vision or colour-vision deficiencies.
WCAG requires that colour is not the only means of conveying meaning, while sufficient contrast is essential for readable content. With charts using three or more colours, the challenge was to find a balanced palette that provided clear differentiation, met contrast requirements, and remained within the approved design system.
Objective
Make data easier to see, understand, and interact with.
Improve visual differentiation across data-heavy charts so users can quickly distinguish information, interact with the experience efficiently, and do so without unnecessary visual strain or errors.
This would help users
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Distinguish data more easily across multi-colour charts
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Identify anomalies, trends, and insights more quickly
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Interpret real-time and historical data with greater confidence
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Reduce errors and cognitive effort when working with complex visualisations
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Make more informed operational decisions from the data
Strategy
Go beyond contrast to make data truly distinguishable.
An accessibility and UX audit revealed that when more than three colours appeared together, users could struggle to differentiate between them and associate chart colours with their corresponding legend labels. Similar colours created confusion and increased the risk of errors when interpreting data.
The strategy therefore considered more than contrast alone - looking at hue, tone, and saturation, along with colour-vision accessibility and the constraints of the approved design system.
Approach
When colour isn't enough, give users another way to see the story.
The process began by evaluating the colours used across the data-heavy charts and identifying where contrast and differentiation could be improved. Since new colours could not be introduced outside the approved design system, accessible alternatives were explored within the existing palette.
Colour was treated as one visual cue, not the only one. Where colour alone could make data difficult to distinguish, patterns and other visual encodings were introduced to reinforce meaning. This allowed users to differentiate chart segments even when colour perception was limited.
The updated visualizations were then evaluated against WCAG 2.2 Level AA requirements, including contrast and the use of colour as a means of conveying information. The experience was also tested with users to understand whether the new patterns, colours, and chart structure were easy to interpret.
We iterated on the proposed solutions through user testing sessions, Subject-Matter Expert reviews, and feedback from internal stakeholders. Based on these learnings, we recommended an Accessibility Mode for users with colour-vision deficiencies, combining multiple ways to perceive and interpret data:
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Patterns - to differentiate data when colour alone was insufficient
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Integrated legends - to strengthen the relationship between chart elements and their labels
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Clear labels and data associations - to reduce interpretation errors
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Screen reader announcements - to provide equivalent information non-visually
This approach ensured that colour was not the only way to understand the data, giving users alternative cues to interpret charts confidently.
Impact
Early validation and accessibility-led UX practices translated into measurable improvements in delivery efficiency and user adoption.
28%
Savings in development time & cost
Early validation through user testing sessions helped identify and address issues before development progressed, reducing rework.
36%
Increase in user adoption
Applying UX methodology and accessibility audit practices improved the overall experience and contributed to increased user adoption.
Highlights
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Accessibility Audit: Identifying barriers across visual, keyboard, screen reader, and zoom experiences.
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Complex Data Visualisation: Making multi-colour charts easier to distinguish and interpret.
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Inclusive Design: Moving beyond colour with patterns, labels, legends, and non-visual cues.
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From Audit to Sign-off: Collaborating, testing, remediating, and validating accessibility through to client handover.