Neither Maghribíya nor any other part of coastal North Africa was EVER 'Black'.Typical Euro-centric ignorance and arrogance.
The Maghreb and the whole of North Africa were originally Black Lands.
The first inhabitants were of Ethiopoid type. They migrated there before anyone else and passed down their to their descendents including their mixed offspring with Eurasians, Eurasian females ,in particular.
The true and original Berbers are from the Horn of Africa; there is a whole region called Berbera in Somalia.
The original and true Berbers of North Africa looked no different than their genetic brothers from the Horn of Africa aka Horners or Ethiopoids.
Europoid looking Berbers are light skinned mulattoes, quadroons, octoroons and quintroons with varying levels of black "Ethiopoid" admixture.
On their father side, their black ancestors were of Ethipoid type. On their mother side, their ancestors came from Eurasia.
There are still a large number unmixed Berbers in North Africa and they are Ethiopoid carriers of the E3b haplogroup. They mostly live in rural areas and southern regions.
Locating the Origin of Haplogroup E-M78
An eastern African origin for this haplogroup was hypothesized on the basis of the exclusive presence in that area of a putative ancestral 12-repeat allele at the DYS392 microsatellite, found in association with E-M78 chromosomes (Semino et al. 2004).
An eastern African origin for haplogroup E-M78 was also hypothesized on the basis of the frequency distribution and microsatellite diversity (Cruciani et al. 2004)
Haplogroup E is the most prevalent haplogroup amongst the Berbers accounting for up to 87 percent of Y-chromosomes among some Berber populations.
Haplogroup E is thought to have emerged in East-Africa and would have later dispersed into North Africa and Eurasia.
The major sub-clades of haplogroup E found amongst Berbers belong to E1b1b1 which is believed to have emerged in East Africa.
Common subclades include, E1b1b1a, E1b1b1b and E1b1b1
E1b1b1b is distributed along a west-to-east cline with frequencies which can reach as high as 80 percent in Northwest Africa.
Only during the Muslim Arab occupation were there any Negroïds brought into North Africa.
NOTHING in that "Cruciani" report suports what you are trying to make appear as actual truth.
What has been merely "proposed" was never proven, and those references never related to the Berbers of the Maghrib who, BTW, overwhelmingly outnumber those few very scattered Saharan tribes.