Can I change the logo, colours and wording on my portal myself, or do I have to ask someone every time?

Yes, most of the everyday look of your portal is yours to change from your own admin area, without calling a developer each time. Your logo, your colours, your company name, the wording on your home page and the contact details in the footer are settings you edit and save yourself, and the change shows on the live site straight away. That is really the point of a white label portal, it is meant to look like your brand and not like a template you borrowed from someone else.

Where it gets more limited is the layout itself. Moving whole sections around, changing how the search box behaves, or redesigning the results page is usually theme work rather than a setting, so that tends to be a job for whoever supports your portal. The same goes for the booking and payment screens, because those pages have to keep working with whatever the supplier sends back, and a completely free hand there would break bookings rather than improve them.

Some things are not yours to rewrite at all. Hotel photos, room descriptions and airline names come from the supplier feed, so you can usually choose what to show and in what order, but you cannot change the supplier's own words. What you can always add is your own content around it, your about page, your terms and conditions, your blog posts and your landing pages, and those are completely yours to write.

Before you settle on a design, ask which parts of your plan you can change yourself and which ones need a request to your support team, and get that answer in writing so there are no surprises later.