Read 'em and weep...
http://www.legislation.gov.uk/uksi/1989/1796/schedule/5/made
"PART IIRequirements relating to optional main-beam headlamps
Any number may be fitted and the only requirements prescribed by these Regulations in respect of any which are fitted are those specified in paragraphs 7, 10 and 12(a) of Part I and, in the case of a motor vehicle first used on or after 1st April 1991, paragraph 5 of Part I."
Para 7 - "Colour: White or yellow"
Para 10 - "10. Electrical connections
(a) Every main-beam headlamp shall be so constructed that the light emitted therefrom
(i)can be deflected at the will of the driver to become a dipped beam, or
(ii)can be extinguished by the operation of a device which at the same time either
(A)causes the lamp to emit a dipped beam, or
(B)causes another lamp to emit a dipped beam.
(b) Where a matched pair of main-beam headlamps is fitted they shall be capable of being switched on and off simultaneously and not otherwise."
Para 12a -"12. Other requirements
(a) Every main-beam headlamp shall be so constructed that the direction of the beam of light emitted therefrom can be adjusted whilst the vehicle is stationary."
So what is illegal abnout spots that can be adjusted, will switch off when full beam switches off, are white etc.
J