Learn Spanish (Latin America): Es un honor haber colaborado con el equipo. - It is an honor to have collaborated with the team.

We use the perfect infinitive (haber + past participle) to show that the action happened before the main verb (Es). While Es un honor colaborar means "It is an honor to collaborate" (happening now or generally), Es un honor haber colaborado means "It is an honor to have collaborated" (the collaboration is already finished).

Since Es un honor is an impersonal expression that triggers the subjunctive, why don't we say que haya colaborado?

You actually can! If you want to explicitly state who collaborated, you use que + the present perfect subjunctive (e.g., Es un honor que yo haya colaborado). However, Spanish prefers using the infinitive—in this case, the perfect infinitive haber colaborado—when the subject is already obvious from the conversation, or when making a general statement.

If a woman is speaking, does the past participle change to colaborada?

No. When you use a past participle with any form of the auxiliary verb haber (like the perfect infinitive here), it always ends in -o. Past participles only change to match gender and number when they are used as adjectives, such as with the verb estar (e.g., la tarea está terminada).