One of the most easy and fast tools to create a monochromatic scheme is Paletton. This is a fantastic tool which is absolutely FREE to use.
Open www.paletton.com in your web browser. The landing page would look similar to how it has been showcased in the image above.
Make sure that you have selected the first color combination option. This option represents a monochromatic color scheme.
Now, you need to identify your choice of base color or Hue for which you want the monochromatic color scheme. For the sake of this example, we shall choose our hue to be Blue.
If you want a specific shade of Blue, then you will need to enter the HEX or RGB color codes of the Blue color of your choice.
This step is necessary only if you DO NOT have a specific value of Blue color. In such a case, you will have to adjust the dots in the inner circle as per your preference.