Yes sir I sure can. These are black and mix in well with the straps and the black under suit.
https://www.amazon.com/gp/product/B01GOK99P6/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
The backpack is not required for basic approval for the 501st Legion. I hope this helps and I have completed many troops wearing the straps. It is very very hard to see them unless you are looking for them.
I will take some photos and upload them later this evening so you all can see what my setup looks like. I even attached a button snap to the straps to prevent the shoulder ammo pouches from sliding down.
You have to be creative here at the MEPD. We are on a low budget and the Empire will not provide any more funding.