I ran into this several months back, on 4.20. Was able to resolve it by hard-coding the color printer in the Crystal form even if printing to a diff color printer.
What was happening was that when sending out multiple e-mails, only the first pdf had the logo in color. All others don't. But the printed copies all print in color. I tried using both the ""e-mail statement customers only"" and ""print or e-mail customers"" settings, but both only resulted in the first pdf having a color logo. I also tried a different printer but same thing happened.