Pics would be helpful . But presuming the only finish it has is oil, then most likely you can restore the color using a teak cleaner, followed by a light sanding (120 grit) and re-apply another oil finish. The cleaner I suggest is this:
http://www.teakdecking.com/index.php?option=com_content&view=article&id=82:tds-tcl-200-teak-cleaner-liquid-msds&catid=12&Itemid=139
Scrub the surfaces AGAINST the grain, rinse well and it's impressive what this stuff can do! On a side note, the color this cleaner brings to cherry is beautiful ...