move color resolution to dataBar options

Author: gzh2003

plugins/ui/src/js/src/elements/UITable/UITableModel.ts

@@ -402,21 +402,28 @@ class UITableModel extends IrisGridModel {
       negativeColor = this.colorMap.get(negativeColor) ?? negativeColor;
     }
 
-    const formatColor = this.getFormatOptionForCell(
+    const barColor = value >= 0 ? positiveColor : negativeColor;
+    const hasGradient = Array.isArray(barColor) && barColor.length > 1;
+    const formatTextColor = this.getFormatOptionForCell(
       columnIndex,
       rowIndex,
       'color'
     );
-    const textColor =
-      formatColor != null
-        ? this.colorMap.get(formatColor) ?? formatColor
-        : undefined;
+
+    let textColor: string;
+    if (formatTextColor != null) {
+      textColor = this.colorMap.get(formatTextColor) ?? formatTextColor;
+    } else if (hasGradient) {
+      textColor = value >= 0 ? barColor[barColor.length - 1] : barColor[0];
+    } else {
+      textColor = Array.isArray(barColor) ? barColor[0] : barColor;
+    }
 
     return {
       columnMin: minRowValue,
       columnMax: maxRowValue,
       axis,
-      color: value >= 0 ? positiveColor : negativeColor,
+      color: barColor,
       // @ts-expect-error TODO: bump web version
       textColor,
       valuePlacement,