How to convert color vector graph into gray-scale vector graph in CorelDRAW Relay

How to convert the color vector map to grayscale, while ensuring that each part retains the character of the vector graph? Don't forget, CorelDRAW also have filters, we try it!

1. First, enter a color vector in the CorelDRAW, as shown in figure:

2. Press ALT+F3 to open the Filter dialog box and press F6 to draw a rectangle larger than the color vector with the rectangular tool, as shown in figure:

3. Fill rectangle is white, select filter effect is "shades of gray", color is black, as shown:

4. Click "Application", at this time you can see the color vector to gray level ~, but this time can not be used ~ ~ ~ then click on the panel "Frozen" command, as shown: