This section is from the book "Complete Self-Instructing Library Of Practical Photography", by J. B. Schriever. Also available from Amazon: Complete Self-Instructing Library Of Practical Photography.
Coloring Portrait Slides. In the first recess on the left of the pallette or to the extreme left of the sheet of glass, place a drop of flesh color and dilute with a couple drops of water. Next to this put another drop of flesh color and dilute with four to six drops of water, for all flesh washes. Next to this put some of the stronger diluted flesh tint from the first recess, mixing a touch of sepia with it, to make a warm brown for tinting the shadows in all flesh parts of the portrait (when these shadows are extremely dark add a tiny bit of yellow); next to this shadow tint put sepia, which is to be used for hair tints or any extra tints needed. Next, cobalt-blue diluted very little; then cobalt-blue diluted weak for all pale blues; next ivory-black diluted very little; next a very little ivory-black diluted weak for outlining the detail work, such as dotting out embroidery and lace.
"THE WANDERING MUSICIANS" Study No. 18 F. Reime.
1015. A drop of rose-madder, gold, lemon-yellow and grey-green should be placed separately on the glass, with space between each color to allow of sufficient room to dilute when necessary. It is very important that the pallette or glass be used systematically,for it saves time and material; also avoids the risk of getting your colors mixed.
Applying The Colors. Before applying any colors the whole surface of the plate should be moistened with clean water. Holding the slide with the head toward you, with a large brush well filled with water, moisten the whole surface of the plate. Work up the background first. Take the medium sized brush, moderately charged with weak color, and wash the background evenly in long strokes. Continue applying the weak color until the correct density and shade are obtained. Wash over large spaces as quickly as possible, so they will not be streaked or spotted. If difficulty should be experienced along this line, reduce by applying, with the brush, water or 95% alcohol.
1017. The light side of the background must be colored with light colors made extremely weak, going over it several times to secure the desired shade. Cobalt-Blue, Grey-Green, Silver-Grey, Gold and very light colors are nice for this, using harmonizing dark shades for the dark side of the background.
1018. In cloud effects, cobalt-blue in the high-lights and red-brown in the shadows give a beautiful effect. Colors must be used stronger in the shadows. To tint the face use the flesh and shadow tints mixed as previously directed.
Having very little in the brush, proceed to color all shadows in the flesh parts of the slide. This gives a round effect to the face, arms, fingers, etc., though great care must be exercised not to get too much onto the slide. After having tinted the shadows, wash over the entire flesh with weak flesh color, beginning in the shadows. Several applications may be used until the desired shade has been secured. This color, however, should be extremely weak, and if repeated applications do not give the desired result, make the solution a little stronger.
1019. Color the cheeks with ruby-red, charging the brush very lightly. Wipe nearly all of the color out of the brush onto a newspaper, before touching the cheeks. The color must be used on the dark side of the face. Use the same color much stronger for the lips, applying it with a No. 1 brush. Use the ivory-black strong, with a No. 1 brush, for eyebrows and lashes, and very weak for outlining and such detailed work as dotting-out lace and embroidery. Use cobalt-blue strong for dark blue eyes and very weak for grey eyes. Strong sepia for brown eyes and weak for hazel. Put the pupil in with strong ivory-black. Color the shadows in dark hair with rather strong ivory-black and with very weak color in light hair; then wash over with whatever tint is desired. Those who cannot mix the colors will find all hair tints in the list of extra tubes given on the circulars, which accompany the colors.
1020. Draperies, flowers, ribbons, etc., should be given the desired shade first, strengthening the shadows afterward with the same shade made stronger. Light articles must be tinted with extremely weak color, and dark with rather strong colors.