I'm guessing the staff room is fairly small... IMO, your best bet is one flash on camera set to TTL and bounced backwards. You're basically using the entire ceiling/wall behind you as a light source. Many would consider this a giant source and "soft lighting"; I just consider it to be "scene fill" (flat lighting). Either way it's not bad lighting, and it can help a lot. You can combine it with whatever other lighting is available quite easily. It can eat a lot of power; so a smaller room is better (to a point), and plenty of spare batteries.
You could set your second speedlight to bounce off a side wall at a fixed power for a bit more direction/character. This would actually be my first choice typically, in TTL and adding the fill/soft light second as needed; but it's not as "safe/easy."
Any bounced light will take on the color of the surface, but light blue isn't a big deal and AWB should fix it. If the room lights have a significant color difference (e.g incandescents) it introduces other issues... one solution would require geling the more direct speedlight, or using only the speedlights as your (effective) light source. But I would suggest just dropping back to scene fill (then the lighting colors mix more and become more universal/even).
Or go "natural light only" if that's an option... but that doesn't really make it any easier to make better pictures, and it makes you very dependent on the situation at hand.
