How To Preserve Spot Colors in Photoshop (version 6 and higher)

Once you have done all this you need to save your image in a suitable file format, which is either TIFF or DCS (Desktop Color Separations). Once you import the TIFF or DCS file into a layout application also the spot color will be imported. If you have a layout application that supports PSD files, such as InDesign, then you can also save your file into a PSD.

There is much more to learn, but it would require a lot of time to explain everything. With this article you have got the basics of how to work with spot colors in Photoshop.