Exactly how many uniforms does the Navy have? Why so many?

I'm going to guess. The Popeye looking ones are junior enlisted dress/service uniforms. White or blue depending on season.
The khaki are for senior enlisted and officer service uniforms similar to army class A.
The remaining three I'm going to guess are dress uniforms for the senior enlisted and officers but the the shades are throwing off my theory about seasonality.
The second from the left I have no clue.
The army had a class A white uniform for use in tropical areas, until at least 2004. Not that I saw anyone wear them, and I was in some tropical zones, I would have shelled out the money.

One more.

I think the Navy needs to consolidate its uniform collection down to 3: 1 "working" equivalent, 1 "business casual" equivalent, and 1 "dress" equivalent. The number of uniform items I have in my closet is absurd. Furthermore, the proposed uniform changes to female uniforms will require me to buy more uniform items (just a couple of days ago, the transition of female chiefs and officers into choker whites was debated on the Female Navy Officers Facebook page, as well as transitioning to a similar design for dress cover). I have not put on SDW's since my commissioning, yet I've paid to change ranks on them and get them cleaned so they don't become discolored. Thus, there's a lot of "closet ornaments."

Off the top of my head here is what I know we have.

NWUs
NSUs (Black Trousers/Khaki Top) E-1/E-6
NSUs (Khaki Top and Bottom) SNCO/Officers
Dress White 1 (E-1/E-6)
Dress White 2 (SNCO/Officers)
Dress Blue 1 (E-1/E-6) Male
Dress Blue 2 (E-1/E-6) Female
Dress Blue 3 (SNCO/Officers)
Dinner Dress Blue (All)
Dinner Dress White (All)
PT Gear (All)

If attached to MARDIV etc.:

MARPATS/Jungle & Desert