Question

why is colour of a flame sometimes blue and sometimes yellow​

Answer 1

Hello mate!

Here's your answer

Blue flames aren't always hotter than yellow flames, because the color of light emitted by the flame can depend on exactly which atoms and molecules are in the flame. ... Sometimes that's more important than the temperature of the flame in setting the color.

Answer 2

Answer:

Glasses of the car are sometimes coloured yellow to prevent the direct harmful sunrays of the sun to enter through the glass.