That's great you look into personality before a person's background, to be honest more people should think like that. But a person's cultural identity would matter to someone you would like to get to know.
If you consider everyone ethnically foreign to look the same if they were from the same continent, you straight away give off ignorance to the point of having personality and unique qualities
Most "visible" minorities in the UK (ie. Asians and Africans), face the same kind of prejudice from the majority population. But obviously we are in the 21st century and things have changed for the better.
It's still inconsiderate to say for example; africans all look the same. It's like saying white Europeans all look the same, but you would agree to disagree on that point, because your familiar with your own ethnicity.
Just look at it from a global perspective, Africa is considered the most genetically diverse continent in the world, since it's where humanity started, but you still consider them all familiar, maybe you only see skin colour
On the other hand, what makes you think you've seen all kinds of Africans. The only africans you've come across in the UK are all from commonwealth countries (which are about 4 or 5 out of 61 other countries), which are made up of english-speaking africans, whilst the rest are either french or their own native tongue.
To be fair on the subject, just search up natives from a west african country like Nigeria. then an east African country like Eritrea , you'd see a huge difference other than skin color, if im correct that's what your indicating. And avoid the negs.