It sounds like you have a colour cast that you need to clean (or keep if you like the effect). In order to clear any colour cast you could:
• Apply a BW filter in Photoshop
• Apply Hue/Saturation filter in Photoshop and set the saturation to minimum (-100)
• Convert the image to BW (in Photoshop: 'Edit' menu, 'Convert to Working Gray') and then save it as Adobe RGB 1998 .
These adjustment can be made in most image manipulation software.