Aj88

Hi guys so I purchased an Audi a3 2003 1.6 the other day and the red oil light has come on (just my luck). The previous owner claims it wasn't on when he had the car which is obviously bs but there is nothing I can do about that. There is no noise coming fromthe engine and today I got the oil filter changed, new oil put in and a new sensor for the oil pressure put in. However after driving about 15 miles the light came on again. I noticed when checking the lights on the dashboard there isn't a yellow oil light it's just red. Does this mean that the red light indicates both low oil and low oil pressure. When the mechanic emptied the oil almost totally we turned the engine on to see if the oil light would come on and it didn't which was obviously very strange. Any thoughts on this? Main question on this model Is there a yellow oil sign?