I expect this has been asked many times !
I've been told the dip beam bulbs in my 2012 RRS are D3S bulbs but the standard ones are very yellow looking so would like to change them for some that appear brighter and preferably with a white light and not yellow or blue light.

I know the brightness won't change but I had 3400k bulbs in my M3 which I changed for 5000k and the light colour seemed to light up better and appear brighter. These were D2S bulbs but not sure if it works the same when using D3S bulbs hence asking the question.

Also where to buy them from as I know eBay is full of cheap copies at not cheap prices. 2017 SVR. SVO Scafell grey Ebony interior
2012 3.0 SDV6 Autobiography santorini black with ebony/cirrus interior. Gone

My D3S are already very white and as far as im aware are the standard Bulbs that came with the car.

If i was going to replace i would probably go for Osram NightBreakers or a Phillips xtreme vision.  2003 BMW M5 - 5 Litres of V8 Optimax Slurping Goodness in Carbon Black

2013 SDV6 HSE Black Edition- Orkney Grey with Ebony & Ivory. LR Facelift RAI, Genuine G4 Expedition Rack, 4x Warn SBD-160 Spotlights, Warn 9.5XPS Winch, Mantec Underbody Protection and Sump Guard, Full Easy Lift Suspension Module, LR Light Guards, Light Force HTX230 Hybrid spotlights, 18” Compomotive PD1881 on 265/65/18 BF Goodrich KO2, ARB fridge, TuffTrek awning 😎

Apparently they came out of the factory with 4300k bulbs which have a more yellow light than white so it sounds like yours might have been changed.
I think it was osram night breakers I put in the M3 so might give them a try. 2017 SVR. SVO Scafell grey Ebony interior
2012 3.0 SDV6 Autobiography santorini black with ebony/cirrus interior. Gone

I fitted OSRAM Night Breaker Unlimited D3S bulbs to my 2010 TDV8 and the difference was substantial compared to the original factory OSRAM bulbs. I did a check of light output using a light meter at 25m and OSRAM's claim of +70% is not an exaggeration. I did the test with the passenger side headlamp using the original bulb and the drivers side using the Night Breaker Unlimited bulb.

The Night Breaker Unlimited bulbs are the same colour temperature (4300K) as the original OSRAM units fitted to the car. I use PIAA Xtreme Force H7 bulbs in the auxiliary high beam lamps and they match the bi-xnon main units perfectly.

I buy from this place, and changed mine to 6000k from stock HIDs. Few years back, one of the HIDs that i bought from this shop for my Freelander 2 failed just before the 12 month, and the guy sent me a replacement the next day.

https://www.hids-direct.co.uk/d3s-35w-hid-...d3s-bulbs/

Hey mates
I want to buy D3S xenon bulbs. I am not interested in the cheaper ones on eBay and Amazon. I googled and found an online store offering it at a reasonable price. But I am not sure about the quality. I have mentioned the link below please suggest if I should buy it or not. Please suggest any better option if you have. Any help will be appreciated. https://xenons4u.co.uk/philips-d3s-xenon-bulb.html

Philips or Osram would be ok. I think Osram were the OEM supplier. I put Osram Nightbreaker in D3S and H7 (for the main beam fill light) and both of the existing bulbs were standard Osram items. 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed