What makes Boro color so special compared to other colors?

Nothing.  Boro is pretty new to offer color as it was made for scientific glass for its low thermal expansion.  About 25 years ago Bob Snodgrass started fuming boro and as the glass pipe market grew, the need and want for color grew.  The cannabis revolution is what mainly pushed the color pallets to grow in borosilicate color.

how many different types of color is there between china color and boro color?

Today there are hundreds of colors made by many many color companies.  China only makes about 15 colors, but these colors are used by American glass companies as cullet to make their new colors.  They use this and add other minerals to change the color some, they also add more clear to help stabilize the color.

Each year there are new colors, what a great industry to be expanding so rapidly.

What do Thermochromatic bangers do?

Supposedly these help let you know when your banger is hot.  Many times the banger is filled with yellow frit.  Yellow glass turns orange and then black as it gets hot.

Using an electric banger like on the Elev8 desktop vaporizers using the dab dish, allows you find your sweet spot, set it and forget it.  Just keep it clean!