in connection with the said signals is altered so as no enable any further instructions to be stored in, or made executable by, the apparatus, the said signals shall not be further used unless that alteration is of a type which has been approved in writing by or on behalf of the secretary or state.
(3) The light signals prescribed by Regulation 31(2) and (4) of the Regulations or those light signals as varied in accordance with Regulation 32 thereof shall not be used unless used in conjunction with the road marking shown in diagram 1001, except that this sub-paragraph shall not apply while works which necessitate the temporary removal of that road marking are being executed don at road in the vicinity of the place where the said light signals are erected.
(4) The containers enclosing the lamps or web or the kinds or light signals mentioned in sub-paragraph (1) or this paragraph shall be coloured black, except that if those containers enclose lamps or the light signals prescribed by Regulation 31(3), 35, 37(2) or 39 of the Regulations, they may be coloured grey instead or black.
(5) Any of the kinds of light signals mentioned in sub-paragraph (1) of this paragraph other than the signals prescribed by Regulation 35 or the Regulations may be mounted with a backing board and if so mounted, the hacking board shall be coloured black and may have a white border not less than 85 nor more than 95 millimetres in width in the case of signals prescribed by Regulation 31(4) of the Regulations and not less than 45 nor more than 55 millimetres in width in the case of the other kinds of light signals which may be so mounted.
(6) without prejudice to the next renewing sub-paragraph, where light signals prescribed by any of the Regulations specified in sub-paragraph (1) or this paragraph are mounted on a post specially provided for the purpose, that part of the post which extends above ground level shall be coloured grey and may have one white band not less than 140 nor more than 160 millimetres in depth the lower edge of the band being not less than 1.5 nor more than 1.7 metres above the level of the surface of the ground in the immediate vicinity.
(7) In the case of light signals prescribed by Regulation 32 of the Regulations, instead of being mounted on a post coloured in accordance with the provisions of the last preceding sub-paragraph, they may be mounted on either a post coloured yellow (but having no such white band as therein specified) or alternatively on a tripod coloured yellow
35. where a sign shown in a diagram in schedule 1 other than a sign shown in diagram 569, 569.1, 603 to 605.1. 651, or 845 to 852 is mounted on a post specially provided for the purpose that part of the post which extends above ground level shall be coloured grey except to the extent provided in sub-paragraphs (a) to (d) below—
(a) in a case where different provision as to the colouring of the post is made in the foregoing provisions or these Directions;
(b) in a case where the post is constructed of concrete, or is supporting is sign placed temporarily on the road in connection with the execution or works or any obstruction thereon and is constructed of timber, then the concrete post shall remain in its natural colour and the timber post supporting such a sign so placed may remain in its natural colour;
