I would say that if they hired you looking for change they are expecting, well, change! So don't be afraid to implement anything you feel will be beneficial.
That said, you are right to be careful not to seem like you want to destroy anything anyone else has actually done, but more-so build on the successes and modernize the approach.
With art curriculum I find that other teachers and administrators know so little about what approaches or standards there are that it will not bother a soul when you change it. This is what I found when I began my position teaching art for both the elementary and middle school in a district in the countryside in Illinois. There was not much in place so no one had any problem with me trying to improve it. I would imagine you would find this to be true as well, but you will find out soon I'm sure.