How can PS be colored to make a sketch effect?

Open a photo of a person in photoshop, preferably with a well-defined face.

2.

Press the shortcut key "ctrl+shift+u" to convert to black and white color.

3.

Copy the layer to get a copy layer. Press the shortcut key "ctrl+i" to convert the copied layer into a negative.

4.

Select the overlay drop-down menu of the copied layer as "Color Fade", and the screen will be so bright that you can hardly see anything. Don't worry.

5.

Select "Blur → Gaussian Blur" under the "Filter" menu, and the blur radius can be set according to the sketch line thickness you need. At this point, the sketch and portrait work has been completed, and the final effect is shown in Figure 2.

Tip: If you are not satisfied and want to do it better, you can use the shortcut keys "CTRL+M" or "CTRL+L" to make some adjustments, or you can use brushes and Bessel pens to make some modifications to the sketch.