Battery

[Terry]

Whent to change battery and found the red cable connected to the negative , had bike from new ?

[airhead83]

It's possible to reverse the polarity on a battery, but you'd need to go out of your way to do it. It will not happen by 'mistake'.
Battery cables don't care what color they are, as long as they're attached properly.
Standard/Industry procedure is red +, black -, but it's possible to use any color... as long as they're attached properly.
From what you're saying, and the 'red cable' is indeed attached to the 'negative' side on your battery...
As long as the 'red cable' is attached to "ground" and NOT attached to the solenoid or starter side of the bike... all is well.