I don't think it would be that noticeable in daylight - and that is the point of turn signals right?
One of my cars has, for the rear turn signal, an amber bulb, behind a white lens (this is the OEM Suzuki light), and it's just not that noticeable - in fact, my son was rear ended in that car be someone who attemped to overtake him whilst he was making a turn - just never saw the signal flashing.
There might also be a legal aspect that you would need to consider - turn signals are required to have a certain brightness or light output.