Red snake dream symbolizes an awareness of rising hidden threats. To see red snakes is an easy task even when they are covertly slithering in bushes, thus red color of the snakes is a symbol of a progressing hidden threat and/or an advanced betrayal being discovered. Red color is an alarming signal which let you to see them and to defend yourself. For them the perfect opportunity to move is missed.
If the red snake bites you, then the dream is trying remind you the importance of this threat. Also, it shows that it has developed to new level and thus your attention has to be directed to it. You need to assess it again, especially paying attention to the progress it has made.
To see a red baby snake in your dream means that a development of a hidden threat is just beginning. Also, it can mean that your awareness to it is too small. You are underestimating this danger.
If you kill the red snake or if the red snake is dead, then it means that you have successfully stopped the progress of this threat. Also, it can mean that you have defended yourself. And your troubles have passed away.