Type ChartAreaStyle
type ChartAreaStyle struct {
// Color overrides the series fill color. A zero color uses the series color.
Color ui.Color
// Opacity multiplies the fill alpha, clamped to [0,1]. Non-finite is zero.
Opacity float32
// Gradient overrides the endpoint colors of ChartFillGradient. Nil fades
// Color (or the series color) using the chart's default alpha stops.
Gradient *ChartAreaGradient
}ChartAreaStyle controls a series' fill independently of its line. The pointer on ChartSeries is optional; an explicit zero Opacity is transparent, so use ChartAreaDefaultOpacity when only the color should change.