I know very little about Vegas chips. But most places in the world would give different codes to two chips of different colors which came out about the same time and of same denomination.

Look at the Flamingo in Campaglia & Wells guide and you will see that they had produced two chips in different times which differed only slightly in color, i.e. 13th iSS $1, A CREAM AND A TAN. AND EACH HAS A DIFFERENT VALUE. IT HAPPENS TWICE WITH .50 AND EVEN HIGHER DENOMS.

So, if two chips, no matter how much they look alike have different values, believe me they cannot be considered the same chip. So, if that is the case, chips of different color cannot be the same. And your chips should be coded differently. Tan and gray are quite different and I bet that eventually they will bring different values..

If I do not have the knowledge, then I have to try to use logic. And, of course a smarter person will come and destroy my simplistic thought process