Just in case you weren't aware - the lights on the bumper are foglights, not driving lamps, so unfortunately driving with them on when the visibility is good is an endorsable offence.
Ignoring that though, I'd definitely be inclined to just match your headlight bulbs, whatever they may be. The light output will be decent and the colour of the light will match.
Until recently, I used Nokya 4000K halogen bulbs which shone bright yellow in both my fogs and headlights and the visibility was pretty good (and 100% legal to have yellow light), but now I've moved across to Osram Nightbreakers in the headlights, and Cree LED H11's (which look OK as 'DRL' style lamps, but do nothing in the fog or on the road lol).
Rob - agreed. I currently have everything LED apart from headlight/main beam, indicators, interior lights. I did have LED indicators up until recently (which were the dogs danglies) however the resistors required to make them flash properly got extremely hot when the indicator was on for more than a few flashes and was starting to melt around where I'd mounted them. (ended up moving them into the BMW where I can just turn off the bulb check in the lighting module and they work properly anyway!).
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