It depends exactly what insulin it is. can you give us the exact name (eg, Humulin I or Humulin M3 etc)?
Some insulins have a mixture of two different sorts of insulin in them, and are supposed to look white and cloudy, others are just one sort and should be clear.
Do you have an instruction leaflet with it? If it tells you to shake it or roll it around in your hands first, then it’s a mixed insulin and should be cloudy.