Thank you for your time.
I have to submit an ad that will print black with spot color (Cyan). Below (Image 1) is the ad that does not contain color separation. The publisher said that I have to provide an ad that allows for color separation, without the ad being changed. Below (Image2) shows how the ad changes when I apply the color separation, with only Cyan being selected. I have also included (Image 3) my color settings; I'm not sure if my color settings have a part in my ad changing. If you know what I need to do to fix this issue, I would greatly appreciate your help.
If your ad contains only Black and Cyan inks you should be able to send the composite PDF and it will separate in the RIP at the publisher. If this is not waht the publisher wants, you need to get verys specific instructions from them. We can help you to understand those instructions if necessary.
The key here is that your images must be true grayscales or Black/Cyan duotones and you must not use any 4-color black elsewhere in the ad. Looking at your screen shot of the cyan plate it looks like the images are grayscale and OK, but your background gradient and black caption bars are showing cyan ink, so unless you used a cyan/black with no magenta and no yellow in them you have a problem. RGB colors cannot be used here.