Red Dot light!!!

Hello!

My 1964 Dart /6 has been idling rough with the ocasional red oil light coming in and off. Today a little red dot light came in and now the car won’t even stay in.

new Spark plugs, New cables, new battery, new distributor cap. Not sure what to check next.

What does the red dot light indicate? Can’t be anything good.

Any help would be appreciated.

Thank you!