I'm going to venture out on a limb and say you might have some action you can take with this one. Of course, you're going to have to negotiate and probalby pay a little extra, but it might be worth it to get your point across.
We have many professional office complexes, and two malls where we do the majority of the work.
As mentioned... it is to keep uniformity and continuity in the given buildings. However, it's biggest advantage is to give the landlords or property managers a nice fat discount for the amount of work we're promised which in all the cases with our customers... they pass the discount over to their tenants. There have been many times, where the tenants have given us files, artwork and/or nothing at all and we either duplicate or re-design things to fit the landlord's taste.... with which we help.
Discuss with your landlord your concerns and I'll bet you anything.... he/she will work with you. It might be as simple as reducing the number of colors, the complexity of your design or whatever.... but his complex has an image to sustain.... and he has hired [
hopefully] professionals to keep that image going............
Just don't use the approach that you are better then his guys or you'll not have a chance with anything.
Down the road, maybe you can slip him/her a brochure of your capabilities and gain his/her respect for future work.