How To Pair Hesh 3 Headphones

Skullcandy wireless earphones flashing blue and red - wont connect to device.I hesh 3 headphones are fully charged.But wont pair with my phone.As soon as i turn on my headphones a red light comes on flashing.Can anybody help please.I have the hesh 3 and they turn on and pair with my phone when on charge but as soon as i take them.