_PURPLE_ is seldom used in simple pen-work, lettering, &c., but largely and with very fine effect in complex illumination. A _reddish-purple_ is to be preferred. A good colour can be made from the purple _stain_ described on p. 175, or from Ruby madder and a little Rose madder, with a very little Ultramarine.
_Simple "Rubrication"_ (see p. 127).--Red letters were most commonly contrasted with _blue_ (the "warmest" and "coldest" colours),[38] in some MSS. with _green_ alone, but more commonly the three [p181] colours were used together, the alterations being generally--
«R»_ed cap._ in columns «RED» in lines of Caps. «B»_lue cap._ of Versal «BLUE» «R»_ed cap._ letters «RED» «G»_reen cap._ (see fig. 93) «GREEN» (see fig. 89). &c. &c.
_Repetition and Limitation of Simple Colours (and Forms)._--The uniform treatment of a MS. necessitates that no colour (or form) in it should be quite singular, or even isolated if it can possibly be repeated. If, for example, there be a Red capital on the "Verso" page, the "_opening_" is improved by some Red--a capital, a rubric, or even a line-finishing--on the "Recto" page. Very often the one piece of colour is very small, and, as it were, an echo of the other (compare Line-finishings and Initials, pp. 205, 193). While it is not always possible or desirable so to treat both pages of an opening, yet, in the book taken as a whole, _every colour used should be repeated as often as there is a reasonable opportunity_. And, therefore, where the opportunities for colour in a book are few and far between, it is well to limit the "colours" used to two, or even one.
This necessity for repetition applies to _simple_ rather than to complex "Illuminated" Forms--_e.g._ a book need not have more than one Illuminated Initial--but within such complex forms themselves [p182] _repetition_ is recognised as one of the first principles of "decorative design" (see p. 215).
_Proportions of Colours._--In Harmonious Illumination, Blue very commonly is the predominating colour; but no exact proportions can be laid down, for the combined colour effect depends so much on the arrangement of the colours.
_Effects of Neighbouring Colours._[39]--When blue and red are in juxtaposition, the blue appears bluër and greener; the red appears brighter and more scarlet. With Red and Green, the Red appears more crimson, and the green, greener and bluër. A greenish blue will appear _plain blue_ beside a pure green; a blue with a purplish tinge will appear more purple. Experiments might profitably be made with simple arrangements of Red, Blue, Green, Black, White, and Gold in combinations of two or more.