Hello all! I have a question regarding titanium coils. I've been vaping for a couple years and recently got into TI grade 1 medical wire on an ipv3li. I'm using the TFV4 rta. I just built a coil at .3 ohms, did some light heating to the wire to get hot spots squared away, and the wire color was blue which I've seen is how it should look. I started vaping and about 30 minutes later, out of interest, I took the rta back off to look at it. The wire has now taken on a grey color. This is after vaping 470 Fahrenheit at 70J on the ipv3. I know the cotton was wicking correctly and it's not like the temperature was heating up, the temp control was doing its job. I've read that grey wire is bad but I haven't come across an explanation why. I know that titanium oxidizes at around 1100 Fahrenheit. My question is, why would gray wire be bad if temp control is keeping the device at around 470 Fahrenheit? That shouldn't be anywhere near hot enough to oxidize titanium. Is there an explanation as to why the color gray is bad when it comes to titanium wire? I've included a picture of the wire so everyone can see what I'm talking about. Any help or explanations would be appreciated!