RGBA (pre-multiplied)
red := color.RGBA{R: 255, A: 255} // opaque red
halfGreen := color.RGBA{G: 128, A: 128} // ⚠ pre-multipliedimage/color
Color models: RGBA, NRGBA, Gray, YCbCr, etc. Understand pre-multiplied vs non-premultiplied alpha.
Common colors
NRGBA (straight alpha)
halfGreen := color.NRGBA{G: 255, A: 128}Gray / Gray16
g := color.Gray{Y: 128}Convert between models
Model.Convert
c := color.NRGBAModel.Convert(color.RGBA{R: 255, A: 128})
r, g, b, a := c.RGBA() // always uint32 0..0xffff