fpSpread1.Sheets[0].Cells[0, 0].Value = 30;
fpSpread1.Sheets[0].Cells[1, 0].Value = 20;
fpSpread1.Sheets[0].Cells[1, 1].Value = 10;
fpSpread1.Sheets[0].Cells[0, 2].Value = 15;
FarPoint.Win.Spread.Model.CellRange celRange1 = new FarPoint.Win.Spread.Model.CellRange(0, 0, 3, 3);
FarPoint.Win.Spread.ThreeColorScaleConditionalFormattingRule rule = new FarPoint.Win.Spread.ThreeColorScaleConditionalFormattingRule(new FarPoint.Win.Spread.ConditionalFormattingColorValue(Color.Aqua, 10, FarPoint.Win.Spread.ConditionalFormattingValueType.Number), new FarPoint.Win.Spread.ConditionalFormattingColorValue(Color.BlueViolet, 20, FarPoint.Win.Spread.ConditionalFormattingValueType.Number), new FarPoint.Win.Spread.ConditionalFormattingColorValue(Color.Green, 50, FarPoint.Win.Spread.ConditionalFormattingValueType.Number));
fpSpread1.Sheets[0].SetConditionalFormatting(new FarPoint.Win.Spread.Model.CellRange[] { celRange1 }, rule);