Coloring SFSymbol in code

I'm currently experimenting with SFSymbol animations for iOS 17.0

I have a custom symbol that I like to animate with the Variable Color effect, and I want to set the colors in code. However, coloring the symbol in code doesn't work. What am I missing?

Image("my-fancy-custom-symbol")        
        .symbolRenderingMode(.multicolor)
        .foregroundStyle(.white, .yellow)
        .symbolEffect(.variableColor, options: .repeating)