Markets Design System
Standardising accessible chart patterns at MDS
I led efforts to make data visualisations easily perceivable and navigable for users with atypical colour vision.
February 15, 2023
Web
Background
Markets Design System (MDS) is an internal suite of tools built to support teams developing applications for the Sales and Trading desks. These applications rely heavily on charts, which help users analyse and interpret real-time and historical market data to make fast, informed decisions.
Recognising that the existing firm-wide design system, Salt, lacked the level of specificity required to meet the complexities of markets apps, we set out to create MDS as a more specialised extension of Salt.
Conversations during this process revealed that a number of users had difficulty distinguishing chart lines, especially in dense, multi-line graphs. This uncovered a broader accessibility issue, particularly for users with atypical colour vision.
Our existing chart system had no built-in accessibility support or standardised visual redundancy. Multiple apps shared this issue, since they reused the same charting patterns. This created risks in decision-making and reduced confidence in the tools.
We needed to solve this at the design system level so teams across the bank could adopt accessible patterns by default.
Role assignment has multiple paths, requiring intentional design for simplicity.
Decoding the Visual Language of Data
We collaborated closely with both the internal research team and accessibility experts to strengthen our understanding, approach and identify behavioural patterns in how users interacted with charts.
I then audited charting tools across Markets applications, mapping usage patterns and identifying breakdowns. Most charts featured 3–8 data series with nearly identical colours and line weights. Legends relied solely on colour, making them unusable for colour-blind users. Tooltips were inconsistent and often unclear.
Role assignment has multiple paths,
What stood out most was the number of makeshift fixes teams had introduced—dashed lines, custom legends, even avoiding certain charts entirely. Some were clever, but all were fragmented, hardcoded, and unscalable. It was a clear sign of both the problem’s depth and the demand for a unified solution.
Possible actions
For organisations needing more control, custom roles allow for more precise permission management. From the roles screen, the admin can create new roles, define permissions by toggling access to actions like viewing financial data or managing SMEs. The role is then available for assignment once the configurations have been saved.
To prevent complexity, the permissions were grouped into categories, with clear descriptions and visual indicators for inherited or overridden settings.
We tested multiple variations of this UI, ultimately settling on the design that used progressive disclosure; hiding more configuration options by default but making them easily accessible when needed.
Design decisions
Using tools like Stark, the Coblis simulator, and in-app prototypes, we validated and iterated on colour palettes, line treatments, and interaction patterns.
The audit had shown that legends were often colour-only and tooltips lacked structure or consistency. Our approach was to introduce a multi-sensory system: combining colour with texture, iconography, and more deliberate line styles to encode data. We also explored dynamic tooltips that adjusted based on context—making it easier to compare values without relying on visual scanning.
Not everything made the cut. We tested patterns like animations and line wiggles, but they added noise rather than clarity. We debated embedding labels directly on lines, but it created clutter in dense data sets. Ultimately, our solution focused on clarity, contrast, and minimalism—balancing accessibility with the fast-paced nature of financial decision-making.
For quick adjustments, roles can also be assigned directly from a team member’s profile. This method is particularly useful when onboarding new users or making individual role changes without navigating away from their details. Admins can simply open the profile, select a role, and confirm the assignment, making the process seamless and immediate.
Batch role assignment is another efficient option. When onboarding multiple team members at once, Admins can select several users and apply the same role to all of them in one action. This is especially valuable for larger teams, reducing repetitive work and ensuring standardised access levels.
Real-time feedback displays affected users and flags any conflicts. For example, If a team member already had a role assigned, the system prompts the user with a warning message to prevent accidental role changes and ensure workflow continuity; particularly important for organisations with strict compliance policies.
If an Admin tries to remove their own access, the system prevents it. Users with lower privileges attempting to edit roles receive a clear message explaining their restrictions and directing them to the appropriate contact. These safeguards ensure a seamless experience, even in unexpected situations.
To maintain transparency, an audit log records every change; who modified roles, what was changed, and when. This helps teams track access adjustments and reinforces accountability. We monitored the audit logs to identify patterns of use, which led to further refinements in role structuring.
Outcome summary
The new permissions feature was added to the beta and significantly improved security and operational efficiency. Admins onboarded team members 40% faster compared to the previous, less structured process. Early data showed a 75% decrease in support tickets related to access issues, indicating that the new feature was intuitive and self-explanatory.
Feedback from beta organisations validated our approach. Users appreciated the feature for its simplicity, while enterprise clients valued the ability to customise permissions when needed. This balance made it easier for organisations of all sizes to adopt the system without excessive configuration overhead.
Subtle praise from the boss.
Learnings
After implementing the feature, the focus shifted to refining usability, integrating feedback, and ensuring scalability. Testing with CSPs improved predefined roles, permission descriptions, and onboarding. Analytics and audit logs enhanced security and compliance.
Looking ahead, the system will likely scale with HR tool integrations and advanced permissions. We plan to introduce automated role assignment rules based on user attributes, further reducing the manual work required by admins.
Now a core part of Ascenda, this feature helps businesses onboard faster, improve security, and scale operations. From a design standpoint, it’s structured yet flexible, driven by the real-world needs of the businesses using it.
And that’s what great design is all about, building systems that empower, simplify, and grow alongside the people who use them.
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Last updated December 2024.