(a) on persons of the class which results if the restriction by reference to colour is disregarded; or

(b) where the original class is defined by reference to colour only, on persons generally.

    (2) Nothing in paragraph (1) shall be taken to alter the effect of any provision as regards any time before the coming into operation of that paragraph.

    (3) Nothing in Parts II to IV shall - 

(a) affect any provision which is contained in a charitable instrument and which provides for conferring benefits on persons of a class defined otherwise than by reference to colour (including a class resulting from the operation of paragraph (1));

(b) render unlawful an act which is done in order to give effect to such a provision.

    (4) In this Article "charitable instrument" means a statutory provision or other instrument (whenever taking effect) so far as it relates to purposes which are exclusively charitable according to the law of Northern Ireland.