Spot inks appear and separate differently from Illustrator or InDesign (CS2 and later) than they do from Photoshop (any version). For example, from Photoshop CS3, using the default Color Settings File, swatch book entry "DIC 35s" separates to process inks as C=33, M=2, Y=64, K=0. From Illustrator CS3, the same swatch book entry, using the same Color Settings File, separates as C=22, M=0, Y=74, K=0.
Historically, InDesign and Illustrator used the CMYK values specified by the swatch book manufacturer. Photoshop has always used Lab values. In CS3 and later, Illustrator and InDesign introduced support for Lab definitions for these swatch books to bring consistency across the three applications.
Set the applications to use the Lab values in the library.
For consistent spot color definitions between Illustrator, InDesign and Photoshop CS3 and later, use Lab values to display predefined spot colors (such as colors from the TOYO, PANTONE, DIC, and HKS libraries) and convert these colors to process colors. To do this, perform the following steps:
Do this in a no document state to affect all new documents, and while specific documents open and active to change their spot ink mode.
If you want the display and output of these colors to match earlier versions of Illustrator or InDesign, use CMYK equivalent values instead.
You must set InDesign Cs2 and later and Illustrator CS2 and later to use Lab values that are in the library; this is not the default setting for either application. When you set InDesign CS2 and later and Illustrator CS2 and later to use the Lab values, you can encode alternate colors for spot colors using the same Lab values. If spot colors are converted to process colors, then Illustrator CS2 and later and InDesign CS2 and later convert those Lab values to CMYK using the Profile selected at print time or using the document profile if the conversion-to process happens before print.
There is no setting to use Lab values in Illustrator or InDesign in versions earlier than CS2. Neither application used different Lab Pantone values; both were designed to use the Pantone CMYK values to define color appearance, while Photoshop uses Lab. This was changed In InDesign and Illustrator CS2.
330728: CMYK values of PANTONE swatches are different in Illustrator and Photoshop