# color The initial color and alpha (transparency) of the particle. ``` var color: SIMD4 { get set } ``` ## Discussion Uses RGBA format where each component ranges from 0.0 to 1.0: - `x` (red): Red color component - `y` (green): Green color component - `z` (blue): Blue color component - `w` (alpha): Transparency (0.0 = fully transparent, 1.0 = fully opaque) --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)