Converting grayscale pdfs to metallic gold

Hi everyone, I just posted this over on the Inesign boards but they suggested I might find my answer over here.  I'm producing a booklet in Inesign for a client. Most of it is grayscale but I have several pages of advertisements that are from gold level sponsors and therefore need to be printed in metallic gold. I've tried using the luminosity trick in Indesign but it left me with dark shades of gold into black, so, on advice from the other boards, I moved the ads into photoshop and created a spot channel. But what I'm getting there is the same.  My background is staying various shades of black and my text is turning gold. I have previous versions of the booklet in front of me and what the client is looking for is the backgrounds in whites and golds. I'm looking for some kind of process I can run all my ads through (they are pdfs) that will achieve this. Attaching some images to help explain. One shows the pdf as I have it - grayscale, the other shows it after a spot color is applied and the last one shows an example of what I'm trying to achieve (different pdf, but you get the idea - the white and gold not the black and gold). I feel I'm missing somehthing really obvious but I'm foxed!  Thanks.