I think that one person has subtly hinted that the image color profile is important, but it need to be stressed that it is critically important for accurate color reproduction. Since the images are being sent out for printing, it is necessary to find out what profile they need because their equipment quite possibly does not perform conversions from one colorspace to another. Even though the images were shot in RAW which means that they do not have a color space associated with them at that point, when the images are processed and then saved as JPG or whatever, it is normal to have some standard profile attached to the image. If the dealer doing the printing expects sRGB and your images have AdobeRGB as their profile, the images will indeed look very drab. Another thing to consider is that when an image is printed it loses a considerable amount of sharpness for several reasons. Therefore, the fix is to sharpen images differently if they are to be printed. In fact, an image that is to be printed will look somewhat oversharpened when viewed on a monitor, but will look just fine when printed. When performing this "output" sharpening make it the last step of post processing and also make sure that the ppi of the image is the same as what is sent to the printer. Worrying about ppi is irrelevant when viewing images on screen, but it is important for printing.