No this two sentences are totally different .穿红衣服的是服务员means The people who wears red clothe is waiter. 穿红衣服的服务员means the waiter who wears red clothe. Hope my advice will help you.

不可以，穿红衣服的人有很多，穿红衣服的是服务员说明只要是穿红衣服的都是服务员，但是穿红衣服的服务员是说服务员中穿红衣服的那个，两者人物的范围不同。

Both are right, depends on how you use it. 穿红衣服的是服务员 equals "The people who wears red clothes are waiters." It's a complete sentence. 穿红衣服的服务员 equals "Waiters that wear red clothes." It's a noun.

Thinking about the situation when you have a dinner in a chinese restaurant,you want to call the waiter wearing rad clothe for service.You should use "穿红衣服的服务员" to call her serving you.But if you want to tell your friend(assuming you and your friend go to the restaurant together) the people wearing red clothe is waiter basing your judgement.You should use "穿红衣服的是服务员".Because "是" equals "is",it always use to express a objective attribute of things.Hope it's useful to you.

The waiter(or waitress) is in red = 穿红衣服的是服务员。the waiter (or waitress) in red = 穿红衣服的服务员。 These two sentences are different. The first one is a complete sentence. It has a complete meaning.The point is telling the reader who is the waiter or waitress. The second one is nearly a phrase. It describes a waiter or waitress wearing a RED clothes. so there is difference between them.