Garden News: Do Iris Change?

     When I moved into my house in 2008 there was a bearded Iris garden already growing.  Most of the Iris were purple.  Over the years I've noticed more and more yellow Iris.  I did a little research.  No, articles claim, Iris do not change colors.  Some colors are more dominant that others and will choke out the less dominant colors.  It seems  also that a particular Iris plant may bloom this year but not next.  Occasionally an Iris will develop what is know as a sport, which is a bud of an entirely different color and while the sport will always bloom the different color all subsequent growth will be the color of the original plant, so so the experts say.
     That may well be true but falls way short of explaining what is going on in my Iris garden this year.  First I noticed two Iris plants, one yellow and one purple, were not like the other bearded Iris.  These plants had flowers that opened with petals that resembled a six-sided star.  Today I found a rustic red growing in an Iris bed.  In the same bed where the yellow star Iris is growing was another unusually Iris.  This one was a pale yellow Iris with one part that was almost white.  The rest of the yellow Iris are a much deeper yellow and the coloration is consistent over the entire flower.  Could this Iris be turning white? 
     If it is it will take several years to confirm.  I've posted three pictures.  The first is a close-up of the different Iris, the second is a shot showing the contrast between the other yellow ones and this one.  The third shot is of a rustic red Iris.  I've never had one and never planted one and unless it hast remained dormant for more than eight years, is a plant introduced by some unknown method.  I'll follow this strange yellow Iris for several more years to determine if it is a mutant or if it really is changing.