So, random question. Went to do my 40k checkup at the dealership for my 2016 Corolla S. They came back and said that my brake fluid was 'dirty' and that I should get my brake fluid flushed. They quoted $185, which I knew was high, so I didn't get it done. Went to another auto shop and they quoted me $100 to get it done next weekend (guy seemed legit and stated how much would be materials vs. time). I don't mind getting this done if I need to, but there seems to be a huge divide on the internet when I googled this, with a ton of people saying you should get it done every 30k miles, or every 3 years, and others saying they've had a car for 10+ years and never flushed the brake fluid. I do live on Long Island, where the moisture is really high year round and the county seems really aggressive with salt during the winter (if that makes a difference).
I guess what I'm asking is: is there a way for me to check my brake fluid to see if it is "dirty"/doesn't look like olive oil, and is it worth it for me to get changed ASAP if it is dirty, or can I wait a while/drive on it? Also, would my brakes be flushed when I get my brake pads replaced/any work done on my brakes?
I'm really "car dumb", and don't mind paying for work on my car, but I also don't want to pay for something that really doesn't need to be fixed (it's a Corolla, not like a Shelby or Audi).