To tell you the truth, my marms change colors all the time. Sometimes they are blue, other times they are reddish brown. I do have a bunch of babeis that are about half an inch to an inch long.
I have them also and I have seen the color change too. I am told hard water can cause the more blue color although I haven't tested this out personally.
I have a batch of baby Marms also if you need a few they are approx. 3/4-1 inch maybe a bit more.