In some ocasions, I tried to do some direct colouring of a black-and-white photography with multiply option, a really easy technique, as you could read in some previous post.
However, sometimes the result in the screen is not matching the desired effect upon printing. Sometimes, it becomes yellowish, or rather quite reddish.
Of course, this is produced by the (lack of) equipment callibration - in fact, I use to work with an USB portable GIMP version over different computers and printers.
A solution: at least, to fix some parameters in my workflow, so that results will be uniform.In this case, I propose the following values' table, which can be useful to produce image collections with a same colour finish between ll of them:
|Colour||R value||G value||B value|
The proposed colours match the traditional chemical processes used to colour photographies.
NOTE: those proposed colours are relatively dark; depending on your photography, you may get a better result when selection the fusion mode "Soft Lighten" instead of "Multiply"...
This is a quick technique, ehough for most cases; however, it does not simulate the original chemical processes properly.
As a fact, depending on the amount of chemicals (in paper or any other support), reaction is slightly different, so that highlights and shadows get different colour shades, too. We will need to work on curves adjustment per channel.
In a few days, I intend to post a new article on image colouring with a "professional" finishing with GIMP...
Are you interested in curves and levels? In that case, don't miss my book "Levels and Curves with GIMP"