Yah definately as the blue ringy blue coloration resemble it being a juvenile..... But as its turning maturity, The colour will slowly change into what its adult form should have.
read from book and a few site on the net, stated that as you know angel are very territorial and could almost not tolerate another adult or same kind in its territory and if this happen fight between 2 adult will occur so the coloration of the juvenile is mostly likely use to tell other adult angel that its not seeking a fight and post no threat to him and so allow the juv emperor to avoid conflict.