According to UK law it's racism. There's not much point in discussing what is and what isn't racism is as it's defined by law.
"The Equality Act 2010 says you mustn’t be discriminated against because of your race. Discrimination which is against the Equality Act is unlawful. If you’ve experienced unlawful discrimination, you may be able to do something about it.
Read this page to find out more about race discrimination.
What’s meant by race?
If you want to make a discrimination claim, you need to find out if you’re someone who mustn’t be discriminated against under the Equality Act 2010.
The Equality Act says it’s only unlawful discrimination if you’re treated unfairly because of certain reasons. These reasons are called protected characteristics. Race is one of the protected characteristics under the Equality Act.
Race discrimination is when you’re treated unfairly because of one of the following things:
colour
nationality
ethnic origin
national origin.
You can be discriminated against because you belong to a certain racial group. People who share the same colour, nationality or ethnic or national origins are part of the same racial group."
More info at: www.citizensadvice.org.uk/law-and-courts/discrimination/protected-characteristics/race-discrimination/