Refer to the code below, the colors of points shown on the scatter chart is not equal to the color list, ColorTemplate.MATERIAL_COLORS.

MyScatterDataSet  set1 = new MyScatterDataSet(yVals1, "DS 1");
 set1.setScatterShape(ScatterChart.ScatterShape.CIRCLE);
set1.setColors(ColorTemplate.MATERIAL_COLORS);

For Example,
while ColorTemplate.MATERIAL_COLORS = [a, b, c, d]
the chart displayed points with colors, [a, a, b, b]

To workaround that, I have override your ScatterDataSet class as shown below.
Then, the colors is displayed as I expected, [a, b, c, d]

public class MyScatterDataSet extends ScatterDataSet {
    static int currentIndex = 0;

    public MyScatterDataSet(List<Entry> yVals, String label) {
        super(yVals, label);
    }

    @Override
    public int getColor(int index) {
        int ret =super.getColor(currentIndex);
                currentIndex+=1;
        return ret;
    }
}

I hope you can fix this bug. Thank you!