Perhaps you should start your work once again, using Lab as the basis for
the definition of the swatch Pantone 288U.
The following example is independent of any CMYK working space.
Photoshop CS2: L34 a+5 b-31
Photoshop CS6: L36 a+3 b-32
Rectangle filled in AI CS6 with 288U, saved as AI
Opened in PS CS6 and measured by Info: L36 a+4 b-32
This color is in-gamut für sRGB and SWOP (no problem anywhere).
Old and new Pantone values are not very different.
PS image converted to sRGB and saved as PNG-24:
Your background color seems to be wrong.
Hope this helps a little.
Best regards --Gernot Hoffmann
Thanks for the response. The one problem I have though, is that colour
swatch you sent, looks nothing like the actual pantone in the Pantone book.
This one seems lavender while the ones we chose from the actual book look
vibrant and less purple) and actually matches the background document more
than the CS6 version.
c: 076 970 2942
I agree. The problem may stem from the OS and the application. I wonder if you are having the application do the conversion? What if you manually created a swatch cosistig of the CS5 equivalents?
Will the stationery be printed on coated or uncoated stock? Will the litho (rather than digital) stuff be printed spot or process? Which swatch book did the client choose the colour from, coated or uncoated? There's quite a difference between the appearance of Pantone vivid dark blue inks printed on coated and uncoated.
The swatch Gernot posted does look to me like 288 U (Pantone 288 ink, printed on uncoated stock). The last swatch you posted looks like 288 C (Pantone 288 ink, printed on coated stock).
Until recent versions, the digital Pantone swatch libraries that came with software, included a somewhat arbitrary CMYK conversion of the coated version, which has been widely misused (in my opinion) for decades, leading to a lot of people having your problem, and blaming it on Pantone or Adobe (unfairly in my opinion).