It is possible to exist more than 1 color code for same resistance-value. I doubt, is there any convention about use only one of them (while manufacture) .
Example : Say an 1 ohm resistor could be expressed as Black-Brown-Black (01*10^0) simply, but when i buy 1 ohm resistors, i always found Brown-Black-Golden (10*10 ^(-1)) being sold.
Example of more than one possible codes for same resistor
Now, i want to know, are the all possible codes correct? or there are some conventions about it?
I would suspect this is done so that there are more significant figures available. For example, you can express a 1.2\$\Omega\$ resistor as Brown, Red, Gold, Gold
But it would not be possible to express this without the third Gold color band.
The first digit is never a zero for standard resistors, so there is a unique code for each value.
Sometimes 0\$\Omega\$ resistors have a single black band.
It's a form of scientific notation: -
If you only have two digits for "a" you cannot express (say) 2.2 with a leading zero. Consistency is the key word.
