Iris Problem and Solution

I want to mix my iris colors after they stop blooming.  I considered different methods but mostly they seemed chancy because the tags might come off during digging them up, piling them, and replanting them.
Today I decided a permanent black sharpie might be my best bet.  So I went to every clump with a bloom and wrote a couple of letters to identify the color to me later.  For example, 2P means two-toned purple.  L Pl means Lydia's Plum (I got it from Lydia).  K Pl means Kelly's Plum (I got it from Kelly).  The two plums are different, but I couldn't think of a way to differentiate them for later other than source's name.
If it rains, it should still work:)