In Photoshop, go to the Image menu: Image > Mode >
What exactly do you mean by »multi-page document«? Possibly a pdf?
Yes, it's a 50 page PDF in black and white that our printer is saying is in color somewhere. I wanted to just test the whole thing rather than separating all of the pages out to see if it is truly black and white.
Maybe you should check in the Acrobat Forum.
Thanks, I will do that.
....I'm wondering if there is a quick way to check a document like this in CS5 programs to see if it is truly in black and white or if there is something in there that is RGB or CMYK.
If by truly black you mean only black in the K channel when printed with a CMYK printer then in Acrobat, choose Advanced > Print Production> Output Preview.
For Simulation Profile choose the profile of the printer. If it is a CMYK printer the Separation Section below will list all CMYK inks.
Uncheck the Process Black, and this will hide all colors on the page that will print only with K. So, if there is no other colors on the page it will be displayed completely white.
Click on the page outside the Output Preview window, to focus the keyboard and mouse input on the document, make sure the page fits in your screen, and press Page down button to go through all 50 pages of the PDF. If all pages are blank (white) you don't have other colors than black, if you see something it uses other colors.
Checking for RGB, CMYK, or any other eventual color spaces of the elements in the PDF is easy. Advanced > Print Production > Convert Colors, then under Document Colors at the top right, click on the arrow and this will show a section with all color spaces used by the elements in the PDF. This however won't tell you any information for particular element - it is just about the color spaces used in the pdf.
Thank you, I went through that process and didn't see any color at all pop up once I unchecked the black. I appreciate the help.