src/vs/editor/contrib/colorPicker/colorPickerWidget.ts/SaturationBox/paint
class SaturationBox:	private paint(): void {
		const hsva = this.model.color.hsva;
		const saturatedColor = new Color(new HSVA(hsva.h, 1, 1, 1));
		const ctx = this.canvas.getContext('2d')!;

		const whiteGradient = ctx.createLinearGradient(0, 0, this.canvas.width, 0);
		whiteGradient.addColorStop(0, 'rgba(255, 255, 255, 1)');
		whiteGradient.addColorStop(0.5, 'rgba(255, 255, 255, 0.5)');
		whiteGradient.addColorStop(1, 'rgba(255, 255, 255, 0)');

		const blackGradient = ctx.createLinearGradient(0, 0, 0, this.canvas.height);
		blackGradient.addColorStop(0, 'rgba(0, 0, 0, 0)');
		blackGradient.addColorStop(1, 'rgba(0, 0, 0, 1)');

		ctx.rect(0, 0, this.canvas.width, this.canvas.height);
		ctx.fillStyle = Color.Format.CSS.format(saturatedColor)!;
		ctx.fill();
		ctx.fillStyle = whiteGradient;
		ctx.fill();
		ctx.fillStyle = blackGradient;
		ctx.fill();
	}