While spending hours stacking chips in the Harrah's New Orleans poker room this week I came across the chip pictured below. One side looks like the standard $5 chip in the ChipGuide (CG00266). The other side is yellow. I haven't seen this variation before and was not able to find any others. Is this an error?

I know there are some Harrah's collectors out there. Can someone tell me what this might be worth? E-mail me with any offers if interested. Thanks.