How do I convert an RGB or CMYK colour to Pantone?
This is not as easy as you might think. There are products that supposedly do a fairly good job of coming close, such as Praxisoft Vector Pro (I have not tested this program), but they're not cheap. And you'll still only be getting a guess.
The best way is to match the colour to a chip from a Pantone Swatch book. There is one made specifically for CMYK matches (it shows a CMYK chip right next to the closest Pantone chip). These, as well, are not cheap.
Finally, you can also type in the RGB or CMYK values into Photoshop's colour palette, and then select "custom" – Photoshop will pick the closest Pantone match. This, however, is the least accurate method.
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