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

No.

While the spelling, grammar, and fundamental meaning of "colega" are identical in both dialects, there are differences in typical usage and pronunciation. In Brazil, "colega" is often used in certain informal contexts as a casual way to address a stranger or an acquaintance (similar to "buddy" or "mate"), whereas in Portugal, it is almost strictly reserved for people with whom you share a professional or academic bond. Additionally, the words commonly paired with "colega" (collocations) vary between the two countries. Pronunciation also differs significantly; Brazilian Portuguese features more open vowels and a melodic rhythm, while Continental Portuguese uses heavy vowel reduction, making unstressed vowels sound much shorter or nearly silent.

Brazilian Portuguese Examples

1. Meu colega de trabalho avisou que ia chegar atrasado. (My colleague told me he would be late.)
2. Ela é uma colega de escola muito legal. (She is a very cool schoolmate.)
3. Preciso falar com um colega sobre o projeto. (I need to talk to a colleague about the project.)
4. Os colegas de classe estão organizando uma festa. (The classmates are organizing a party.)
5. Ele é meu colega de academia. (He is my gym buddy.)

Continental Portuguese Examples

1. O meu colega de trabalho avisou que ia chegar atrasado. (My colleague told me he would be late.)
2. Ela é uma colega de turma muito porreira. (She is a very cool classmate.)
3. Preciso de falar com um colega sobre o projeto. (I need to talk to a colleague about the project.)
4. Os colegas de turma estão a organizar uma festa. (The classmates are organizing a party.)
5. Ele é o meu companheiro de ginásio. (He is my gym buddy.)