Is the word loiros the same in Brazilian and European Portuguese?

Yes

The only difference between "loiros" in Brazilian Portuguese and Continental Portuguese is pronunciation.

• Vowels: In Brazil, the diphthong "oi" is typically more open and distinct. In Portugal, unstressed vowels are often more closed or "reduced."
• The "s" sound: In many Brazilian dialects (such as in Rio de Janeiro), the final "s" is pronounced as "sh" [ʃ], similar to Portugal. However, in many other Brazilian regions (such as São Paulo or the interior), the "s" is pronounced as [s]. In Portugal, the final "s" is almost universally pronounced as "sh" [ʃ].

Brazilian Portuguese Examples

1. Meus irmãos são loiros. (My brothers are blond.)
2. Aqueles meninos loiros estão brincando no parque. (Those blond boys are playing in the park.)
3. Os loiros da nossa turma são muito engraçados. (The blondes in our class are very funny.)
4. Eu vi dois cachorros loiros correndo na rua. (I saw two blond dogs running in the street.)
5. Tem muitos loiros naquela foto. (There are many blondes in that photo.)

European Portuguese Examples

1. Os meus irmãos são loiros. (My brothers are blond.)
2. Aqueles meninos loiros estão a brincar no parque. (Those blond boys are playing in the park.)
3. Os loiros da nossa turma são muito engraçados. (The blondes in our class are very funny.)
4. Eu vi dois cães loiros a correr na rua. (I saw two blond dogs running in the street.)
5. Há muitos loiros naquela fotografia. (There are many blondes in that photograph.)