yellow oil light

just wanted to see if anyone had any quick answers before or while I search for my answer on here. on my old e36 a red oil light would come on as soon as I shut off the car and that was when I needed to add oil, the light came on when the oil level was at the low line of the oil stick. now on...

About a year ago I replaced the oil level sensor on my '00 328 / 130k, as it was coming on after startup. I've only driven about 5k since then. Last few weeks the oil light has been coming on after 10-15 mins of driving, or coming on after switch off. Oil is definitely at the correct level -...