YOU SAID:
my car is red and my hat is blue
INTO JAPANESE
私の車は赤で、私の帽子は青です
BACK INTO ENGLISH
My car is red and my hat is blue
INTO JAPANESE
私の車は赤、私の帽子は青です
BACK INTO ENGLISH
My car is red and my hat is blue
That didn't even make that much sense in English.