Last week I bought a candy/deep fry thermometer. I think I bought it at Walmart.
Last night I started to heat the oil to fry flounder and I couldn't see the temperature indicator (or whatever you call it). I called my wife in and she told me it was a pinkish color
I'm color blind and I can't see it, so worthless to me. Fortunately I also bought a digital probe type that goes up to 450*.
Any cooking store should have choices, and of course online