In a county operated senior center, what rights do the seniors have in regard to their environment?

Another consideration - in some states or counties the organization may be subject to inspections that are open to public record. Records may be viewed by families, job applicants, funders or others. It's true - if a budget includes upgrades in 2014, it's likely offered only this year. Those funding a project often set the parameters in terms of cost, safety, appearances, ease of entry/exit. Grants are very specific in regard to what the money can be used for. If it's county funded, it will come with specific requirements. Please let us know the source of funding if you can. I agree it is important that a place be in such a condition as to attract new people.

Typically, the budget to upgrade furnishings and decor is not available at all times. When a manager gets money to re-furbish a room, they'd be crazy not to do it. It could be a long time before they'd have that opportunity again – the money gets spent somewhere else.
I understand that familiarity is important to many but, in the bigger scheme of things, the condition of the furnishings is pretty important, too. To you it may look homey and familiar, to someone new (and it's very important to keep attracting new residents/members), it may just look tired or even shabby.

Familiarity and routine are important to people, especially the elderly, and even more so for people with dementia, who easily get confused. I'm sure the administrator's heart is in the right place to "spruce up" the surroundings and make it more current or prettier, however it is something I would talk to them about because I totally understand why you are asking. It would be akin to someone coming into my home and changing out my furniture or decor without asking me. Then it wouldn't feel like the home I was used to anymore. That might be something you could mention to the administration there.

New administrators can mostly do what they choose as long it does not change the characteristics of the agency's stated mission AND does not impinge on other's safety. If the old setup is just comfortable and something everyone is used to, it may be best to just try it out rather than start sparring with a new administrator. If you really discover any specific arrangement she makes is just difficult then you may be able to reason with her. New administrators sometimes feel they must "change" or "improve" something. At this point it will be your responsibility as a group to communicate with her. Be specific as to WHY it's not working. Leave personal preferences out of this equation.

Unless they are steppping on ADA rerquirements you really do not have rights to determine anything. It is run by the County, if you do not like the adminstrator's decisions you have the right to complain or not vote for the politicians who appoint this person. In some Counties politicians are very beholden to the elderly because they are a dependable voting block. Call your Commissioner, they may call the administrator for you.