As above, helmet lights do weird things if they aren’t dimmer than your bar ones – to my eyes at least.
Whiteness can be useful though. I used to have two similar lights, one with old fashioned LEDs (ie not cree types with drivers) a good few years ago, and one with a halogen bulb. Both were similar brightness, not really enough to see by. I used to use the LED one fine, but one day I took the halogen one and I suddenly got people pulling out in front of me all over the place.
The halogens were the same colour as everyone’s car headlights, but the white LEDs were much more noticeable.