The DUI is not worn with the Dress Blue Uniform.

You wear your regimental crest with Blues.  Also with Mess.
Boy are you guys wrong on uniforms, let me help you up.
The Blues are NOT a replacement for a tuxedo.  That would be the evening mess.
Blues are a duty uniform for formal occasions.  Worn with a necktie before 1700 and cover and worn with a  bowtie and no hat after 1700.  The blues have recently substitued for the mess, which in formal days, was the only acceptable uniform for dining in the officer's mess (hence the name, dress mess).
The dress whites are a copy of the Green's in a white fabric that substitue for Blues in warmer climates.
There is also a summer mess which is a white jacket and black pants.
Blues may wear full size medals or ribbons (but NOT miniature medals, though I have seen f-d up fat boys do it.  Its authorized by the reg, but you look like a dork)
With mess, only miniatures are to be worn.
Mess, for those that have seen it, basically looks like a bartender's jacket.
Blues are worn under arms, but the mess is not.

Since the blues are a duty uniform, I think that the CSA's decision to get rid of the greens and only have blues is a good call.  Just need TW's to cover for the B's.

I am a walking 670-1.  Which, btw para 28-23 covers the wear of the RDI.

ETA para of 670-1 that covers the wear of RDI with Blues.

Aviator, checking out your blues, you are goofed up.
You would wear your regimental crest above your name tag (no name tag, btw, during evening wear, though with 4-1 you do wear it (as you are doing))
And to be super anal, 1/4" for the wear of a class 3 badge(your aviator wings are class 3) above the top ribbon.  You look way closer than 1/4" in your picture.