Cedars turn a brown/golden-red colour during harsh growing conditions such as hot summers and cold winters. This does not mean your cedar is dead! As long as the branches return to their natural green colour you don’t have anything to worry about.
However, another reason cedars turn brown relates to transplant shock. All trees dug out of the ground experience some level of this. If the transplant shock is very severe, your cedar tree may end up completely brown within a couple months suggesting that it was improperly dug. Lastly, cedar trees suffering from drought may also turn brown (after turning a lighter shade of green) as they react to the stress. This relates to a lack of water getting to their root systems.
Be sure to make sure the soil your cedars sit in is always moist. As well, buy cedar trees from a reputable company that backs up their trees in case of improperly dug cedars.