Significantly more than a handful: All of the later batch of then-Neville Hill based units, 142072 - 096, received Regional Railways livery, as well as 142015/016, 142023/024 and 142071. 142023, a Newton Heath based unit, was in fact the first unit to carry Regional Railways livery upon its launch in 1991.
There were also some Newton Heath units that carried Regional Railways livery in lieu of the GMPTE dark grey/white/red livery that was otherwise being applied to these units in the mid nineties, due to some sort of disagreement between GMPTE and BR. Certainly some units in the 14204x series were so treated (The Merseyrail yellow livery that such units subsequently wore was something of a latecomer to the party).
Provincial was the livery with a light blue base colour with a wide dark blue waistband and white borders, while Regional Railways had a dark blue windowband, a light blue stripe and light grey lower panels (and cantrail, in most cases).
144011 - 013, I believe.