What causes Color over Lifetime not applying to Unity particles?

The Color over Lifetime gradient multiplies the particle's start color and the material color, so a black start color or a shader that ignores vertex color cancels the gradient out.

How do I catch this when it only happens for some players?

Capture it automatically from the player's device with the full stack trace, the device and OS, the build, and a breadcrumb trail of what they did. That turns a vague complaint into a specific, reproducible issue you can fix without owning the hardware it happens on.

How to Fix Particle Color Over Lifetime Not Applying in Unity

Quick answer: Set the start color to white, use a particle shader that reads vertex color, and confirm the Color over Lifetime module is enabled with a visible alpha gradient.

Color over Lifetime is multiplicative against start color and vertex color. If either input is black or the shader drops vertex color, the gradient does nothing. Here is how.

How to fix it

1. Set start color to white

The lifetime gradient multiplies the Main module's Start Color. Set Start Color to white so the gradient's colors come through at full strength instead of being darkened or zeroed.

2. Use a vertex-color shader

Particle tint is passed as vertex color. Use a material whose shader multiplies by vertex color (the particle shaders do); a generic opaque shader ignores it and shows no color change.

3. Check the alpha keys

Make sure the gradient's alpha keys are not all zero or fading out immediately. A gradient that drops alpha to zero at time 0 makes particles invisible rather than tinted.

Catching the ones you can't reproduce

The hardest version of this to fix is the one you can't reproduce — it only happens on a player's hardware, OS, driver, or save state, under conditions that simply aren't present on your machine. A report that says “it crashed” or “it froze” gives you nothing to act on, so the bug survives release after release while quietly costing you players.

Automatic error capture closes that gap. Each failure arrives with its full stack trace, the device and OS, the build number, and a breadcrumb trail of what the player did right before it broke, so even a failure you have never seen becomes a specific, reproducible issue. Fold identical failures into one signature ranked by how many players each hits, and your worklist sorts itself worst-first instead of arriving as a stream of vague complaints.

This is where a tool like Bugnet earns its place. Its SDK captures every Unity error automatically with the full stack trace plus device, OS, memory, build, and game-state context, folds duplicates into one grouped issue with an occurrence count, and ties each to the build it first appeared on — so you fix the problem that hurts the most players first and confirm it is gone when its signature disappears from the next release.

Most of the time the fix is small. Seeing the failure clearly is the part that actually costs you.