what headlights are these?
 

these are regular halogen headlights, correct?

I want to upgrade to a whiter light on both the headlight and smaller light next to it - to match the fogs


https://cimg8.ibsrv.net/gimg/www.mbw...ebd53b86a3.jpg

You don't say what year it is but from the pic they do look like regular halogen bulbs, the outer bulb looks a little strange, like there's something on it but I'd bet it's halogen if it's factory. There are lots of easy changes, Sylvania and Phillips make several grades of plug in bulbs that are brighter and whiter (higher Kelvin rating such as 6000 etc) and then there are LED retrofits that range from crap to quality. One issue for the LEDs is to make sure they are CAN compatible so you don't get error messages from the computer.

When I got my 2013 C250 coupe, I decided to upgrade the exterior lighting to match the daytime running lights. I did the parking lights, low beams, high beams, mirror puddle lights and clear side markers. For the parking lights and the puddle lights on the mirrors I used LED wedge bulbs from AZN optics. The low and high beam lights were replaced with Phillips Diamond Visions H7s. The car looks great. I also replaced the side markers with clear lenses and stealth bulbs. This really makes the car look great. One word of caution regarding the puddle lights: get to know your service advisor at the dealership and see if he/she can have one of the mechanics swap the bulb. I only mention this as it's a horrible DIY project and if you break the auto dim glass, I was quoted $600 to replace.

The problem with doing the exterior lights is that you will get tempted to replace the 7 interior bulbs as well. I have yet to replace the interior, but again would use the wedge bulbs from AZN as they have been working fine and look great.

Standard halogens. Simple upgrade would be to just replace with higher quality halogen bulbs, but you'd still have a fair amount of yellow injection. DV bulbs are probably the whitest ones on the market, but you get reduces lumen output which is why they're only rated for off road use. Still, they'll be fine if you mainly drive on well lit streets. Otherwise, what you can do is go with an HID conversion which will give you the brightness and the whiteness. To really do it right, you'd do an HID projector retrofit along with the conversion to focus the beam and not use the built in reflectors.