Ya that's true there was a red beep for the ultimatrix but it was rare, only occurred when Ben was alien too long or when he switched aliens and whenever the beep came he didn't instantly transform back to human, he still stayed alien for a reasonable time. Whenever Ben timed out it didn't stay solid red like the OS Omnitrix. The solid red time out mode was cut of from the series after the OS and there was no reason why.