How to Remove Colors in the Acrobat Output Preview
- 1). Open the document you want to remove color from in Adobe Acrobat Professional.
- 2). Click "File > Print" to load the "Print Production" panel. Click "Preflight."
- 3). Click the ">" next to "PDF fixups."
- 4). Click "Convert to grayscale" and then "Anaylze and fix." The preview will automatically update. If you want to publish this version, click "Print."
Source...