Colt briefly sold the 6900 rifle.
It was a simplified AR made by a contractor.
It didn't have an ejection port cover, no hard chrome plating in the bore, and had a free floating barrel and hand guard.
It seemed to be set up more as an inexpensive accuracy rifle.
The Colt model you're asking about is not a dream, it's the LE6900 Light Carbine which they showed the first time at the 2013 SHOT Show back in January, then after the show it was released to the dealers, there are several members here that have them.
If you download the Colt 2013 catalog from the Colt site and take a look at page 39 at the lower right corner of the catalog, the descriptions are there but without any picture.
Currently that model had been discontinued but the reasons for that was not clear from the factory, but I had seen that same carbine had been reincarnated as a Colt Competition model CSR-1516 which is a Colt Competition Rifles sporting rifle line, in other words a basic starter competition rifle. Bold Ideas of Texas makes the Colt Competiton rifles.
The new model CSR-1516 is similar to the LE6900 Light Carbine except they changed the handguard to a 12 inch (the LE6900 had 9.5 inch), there are now four long vent slots on the new handguard, the A2 grip are changed with a Hogue overmolded grip with Colt logo, the buttstock is the same M4 with quick disconnect sling mount exept it have a Colt logo now.
Other features of the new CSR model are the same as the old LE6900, it still have the same 16" non chrome lined 1/8 twist barrel, now marked differently with the Colt word stylized logo 5.56 NATO 1/8 and a new style Colt competition closed bottom flash suppressor, the upper receiver is the same without ejection port cover, no forward assist and the lower receiver trigger guard is the same fixed enlarged, non folding.
Here's an article about the new Colt Competition CSR-1516 model with video review from Gunblast.com.