fix: fix the color of series label, #37

bar_chart.go

@@ -168,16 +168,18 @@ func (b *barChart) render(result *defaultRenderResult, seriesList SeriesList) (B
 			}
 			y := barMaxHeight - h
 			radians := float64(0)
-			var fontColor Color
+			fontColor := series.Label.Color
 			if series.Label.Position == PositionBottom {
 				y = barMaxHeight
 				radians = -math.Pi / 2
+				if fontColor.IsZero() {
 					if isLightColor(fillColor) {
 						fontColor = defaultLightFontColor
 					} else {
 						fontColor = defaultDarkFontColor
 					}
 				}
+			}
 			labelPainter.Add(LabelValue{
 				Index: index,
 				Value: item.Value,

horizontal_bar_chart.go

@@ -155,15 +155,18 @@ func (h *horizontalBarChart) render(result *defaultRenderResult, seriesList Seri
 				X:         right,
 				Y:         y + barHeight>>1,
 				Offset:    series.Label.Offset,
+				FontColor: series.Label.Color,
 			}
 			if series.Label.Position == PositionLeft {
 				labelValue.X = 0
+				if labelValue.FontColor.IsZero() {
 					if isLightColor(fillColor) {
 						labelValue.FontColor = defaultLightFontColor
 					} else {
 						labelValue.FontColor = defaultDarkFontColor
 					}
 				}
+			}
 			labelPainter.Add(labelValue)
 		}
 	}