problem merging color and grayscale images

[astevens7911]

I am trying to merge two images, one is red fluorescence and one is just a bright field image (grayscale).  I am using the command image > color > merge channels.  In the drop down boxes, I select the correct files, one under red and one under gray, with "none" listed under green and blue.  When the new image is made, the red channel is correct but the image that is supposed to be gray is green.  The images are tif files and 16-bit.  What am I doing wrong?  

Any help would be appreciated.

Thanks!