After I discovered that the Post Office only had outdated forms I managed to get through to DVLA (blimey!) and they told me that printing a D4 in black and white is acceptable, but photocopies aren’t.
And they sent me an email:
DVLA Contact Centre dvla.donotreply@dvla.gov.uk
Tue, Feb 8, 9:46 AM (7 days ago)
Dear Skel
Thank you for your enquiry received on 8/2/2022.
Your case reference number is XXXXXXXX
We appreciate that you have taken the time to contact us in relation to this matter.
I can confirm that you can print out the D4 form, which can be black and white or in colour.
I hope this information finds you well.
Do not reply to this email. If you wish to contact us again about this response then please use our reply form link or copy and paste the following URL in to your browser:
Best Regards
X XXXX
DVLA Email Logo
Also, I’ve just done a D4, and the company told me that they will accept photocopies if they lose the original, but the copy has to be signed by the original doctor. So take a copy before you post it.
Having recently, er, reshuffled my working arrangements 
, I’m looking to get through the C test ASAP - I’ll be speaking to a recommended school in the next couple of days, I appreciate that they’ll probably have the form - but as its available online, IF my GP will do a medical for a reasonable price, can I print the form in B&W to save waiting on the post?
i would not send a copy they tend to return them.
they may accept it one but it’s not worth taking the chance
STEP 1
Have a medical to prove you are physically fit to drive a Large Goods Vehicle using Form D4 of the pack (obtainable from various driving schools).
Download the 8 page D4 Medical FormUsing this Link Please print and take to your GP if you have the facilities at home or work.
Please contact your GP or visit www.driversmedicals.com who can provide low-cost medical examinations.
THIS LINK will take you to a list of some cheap medical places around the UK.
The downloaded form is acceptable.
Rog wrote:-
The download form is acceptable.
Indeed it is, but PeteG wants to know if a black and white printout of it ok - the downloaded one is a colour one, and he may only have a monochrome printer.
I can see no reason why it won’t be accepted, but to be on the safe side a quick phone call to DVLA would be wise. Your doctor won’t be happy if he has to re-do the form!
When I did my medical the training provider had the D4 forms so I didnt need to get 1 they also sorted the Dr out so didnt have to look for that either
Not sure if they would accept a b/w copy but I wouldnt risk it you could phone them up and request 1 to be sent out they dont charge for them
Can i ask who you doing your training with 
As I said Tyne & Wear LGV arranged everything from medical all forms to test
Smart Mart:
Rog wrote:-
The download form is acceptable.
Indeed it is, but PeteG wants to know if a black and white printout of it ok - the downloaded one is a colour one, and he may only have a monochrome printer.
I can see no reason why it won’t be accepted, but to be on the safe side a quick phone call to DVLA would be wise. Your doctor won’t be happy if he has to re-do the form!
Thanks - I have never downloaded one and did not realise it was in colour - I am enlightened 