2d - How to Convert Rasterized images to a single Spot Color in Adobe Illustrator?
Step 1: Make sure the PMS Spot Color is present in Swatch Pallet.
Step 2: Select the Rasterized image.
Step 3: Select Convert to Grayscale from the Edit Drop Down menu.
Step 4: While the Grayscaled Art is selected choose the PMS Color from the Swatch Pallet.