# Day 24: Custom Colormaps — Making Simulation Data Actually Readable

Subtitle: Because bad colors hide good data

This feature didn’t start with a bug. It started with a realization.

Even when the simulation was correct — sometimes the visualization wasn’t helping.

Colors were there. But clarity was missing.

Day 24 fixes that.

* * *

## The Problem

Most default charts use generic color schemes.

They work — but not for research.

Issues I noticed:

*   Hard to distinguish values in dense regions
    
*   Poor contrast in certain ranges
    
*   Not accessible for colorblind users
    
*   No consistency across different charts
    

👉 The data was right, but the interpretation was harder than it should be.

* * *

## What’s New

Sionna Visualizer now supports **custom colormaps**.

Users can switch between multiple palettes:

*   Viridis (scientific standard)
    
*   Plasma
    
*   Inferno
    
*   Cool/Warm
    
*   Grayscale
    
*   Colorblind-safe palette
    

Each palette is designed to improve readability for different scenarios.

* * *

## How It Works — Color Mapping Layer

Instead of hardcoding colors, charts now use a mapping function:

```id="cmap1"
value → normalized range → color scale → rendered output
```

Every data point passes through this pipeline.

This allows:

*   Smooth gradients
    
*   Better contrast
    
*   Consistent visual meaning
    

* * *

## Frontend — Dynamic Palette Switching

Angular now includes a colormap selector.

When the user switches palette:

*   Charts re-render instantly
    
*   No need to rerun simulation
    
*   Same data, different perspective
    

* * *

## One Subtle Challenge

Not all colormaps behave the same.

Some exaggerate differences. Some compress them.

Fix: → Normalized value mapping before applying color

This ensures consistency across all palettes.

* * *

## Why This Matters

In research, visualization is not decoration.

It’s interpretation.

A poor colormap can:

*   Hide patterns
    
*   Mislead analysis
    
*   Reduce clarity
    

A good one can:

*   Reveal trends instantly
    
*   Highlight anomalies
    
*   Improve understanding
    

* * *

## The Bigger Shift

This feature moves Sionna Visualizer from:

→ “Displaying results” to → “Helping interpret results”

That’s a big difference.

* * *

## What’s Next

Day 25: Starting Phase 3 — The Shift to a Research Platform

Because visualization alone is not enough anymore.

* * *

Sionna Visualizer — github.com/Vinu2111/sionna-visualizer Live: https://sionna-visualizer.vercel.app

NVIDIA AI Aerial / 6G Developer Program Building in Public — Day 24