If you're not using a two point sling, you're messing up. The best way to sling your bb gat is on a two point sling, and cool colors make you cool thats just how the internet works. We don't make the rules we just follow them. The Vtac styled sling is one of the most prolific variants of two point slings, a tried  and true design thats easy to use, fast, and comfy. There's a reason we use them, they're well worth the investment. Don't break your plastic body m4 because you didn't have a sling. 

vtac mk2: vtac strap

tactical sling: safari rifle sling

tactical gear: sling

Sling Strap: Shoulder Strap