Help! I have blue highlights

When you say no well known salons, does that mean none at all? Even the small unknown ones would have better tools to fix it that you would have at home...I'd just talk to them, ask them your problem and see if they sound like they know what they're talking about when you discuss solutions.

If there are NO salons at all near you. Can you separate out what's blue and just dye that separately, not touching the rest of your hair? You would need to put something red (ideally more orange) over them to counteract the blue. If they aren't VERY blue, but just a blue cast, don't leave it on very long, and don't choose straight red...choose a brown that's close to your hair color but obviously has some red in it. Be sure to do one as a test strand before you do all of them. You may wind up with reddish highlights in your ash hair, so it may not look that good. This will be pretty risky.

.....Probably a better option is to get an orange/red color depositing shampoo. It just puts pigment on your hair and washes out when you use a normal shampoo. Complements makes one you can buy at Sally beauty supply, other brands also make them. You will need something orangy to counter the blue.

The shampoo is probably the best solution because the blue may fade to something you like over time (if its not THAT blue that is, but more of a blue cast), so the shampoo will help cover it as it washes out over time.