[p5.js 2.0 Bug Report]: Friendly errors do not prevent runtime exceptions in color APIs

Most appropriate sub-area of p5.js?

• Accessibility
• Color
• Core/Environment/Rendering
• Data
• DOM
• Events
• Image
• IO
• Math
• Typography
• Utilities
• WebGL
• Build process
• Unit testing
• Internationalization
• Friendly errors
• Other (specify if possible)

p5.js version

2.2.0

Web browser and version

Google Chrome Version 144.0.7559.61

Operating system

Windows 11

Steps to reproduce this

Description:
While testing p5.js 2.0 color-related functions, I noticed that several APIs emit a Friendly Error but still throw runtime exceptions (e.g. TypeError or uncaught Error), causing sketches to crash.

In p5.js, a Friendly Error is generally expected to safely handle invalid input without crashing execution. However, this behaviour is inconsistent across color APIs.

Steps:

1. Run the sketch given below
2. Observe that it throws an FES error but still sketch crashes

Snippet:

function setup() {
  noCanvas();

  let c1 = color(255, 0, 0);
  let c2 = color(0, 0, 255);

  // Case 1: lerpColor crashes after friendly error
  console.log(lerpColor(null, c2, 0.5));

  // Case 2: invalid color string crashes
  background("");
}

Observed Behaviour

1. Friendly Error is logged
2. Sketch then crashes with:

• TypeError: Cannot read properties of null
• or Error: Invalid color string

Expected Behaviour

Friendly Error should:

1. clearly report invalid input
2. prevent runtime exceptions
3. allow sketch execution to continue safely

Additional Notes
This pattern occurs in multiple color-related APIs (background, fill, stroke, color, alpha, lerpColor). Some functions correctly handle invalid input after emitting a Friendly Error, while others still throw.

I'm willing to implement a fix if this gets approved

Start by running the supplied setup() sketch and inspect the color API entry points named in the report: background, fill, stroke, color, alpha, and lerpColor. Compare how each handles invalid input after reporting a Friendly Error; done means the affected APIs report the error without uncaught runtime exceptions and allow sketch execution to continue.