tle reddish
yellow, ochre say, and possibly a little reddish blue, new blue or
ultramarine; add these, and see how it grays it and still keeps the
same kind of green. This is the principle in extreme. Still, the best
way would be not to try to make a green of Prussian blue and chrome
yellow. It is better to know the qualities of each tube color on your
palette. Know which two colors mix to make a crude color, and which
will be gray, more or less, without a third.

=Muddy Color.=--Dirty or muddy color comes from lack of this last. You
do not know how your colors are going to affect each other. You mix,
and the color looks right on the palette, but on the canvas it is not
right. You mix again and put it on the canvas; it mixes with the first
tint and you get--mud. Why? Both wrong. Scrape the whole thing off.
With a clean spot of canvas mix a fresh color. Put it on frankly and
freshly and let it alone--don't dabble it. The chances are it will be
at least fresh, clean color.

Over-mixing makes color muddy sometimes, especially when more than
three colors are used. When you don't get the right tint with three
colors, the chances are that you have got the wrong three. If that is
not so, and you must add a fourth, do so with some thoughtfulness, or
you will have to mix the tint again.

=Dirty Brushes and Palette.=--Using dirty brushes causes muddy color.
Don't be too economical about the number of brushes you use. Keep a
good big rag at your hand, and wipe the paint out of your brush often.
If the color is getting muddy, clean your palette and take a clean
brush. Your palette is sure to get covered with paint of all colors
when you have painted a little while. You can't mix colors with any
degree of certainty if the palette is smeared with all sorts of tints.
Use your palette-knife--that's what it's for. Scrape the palette clean
every once in a while as it gets crowded. Wipe it off. Take some fresh
brushes. Then, if your color is dirty, it is your fault, not the fault
of your tools.

=Out-door and In-door Colors.=--There is one source of discouragement
and difficulty that every one has to contend against; that is, the
difference in the apparent key of paint when, having been put on
out-of-doors, it is seen in the house. Out-of-doors the color looked
bright and light, and when you get it in-doors it looks dark and gray,
and perhaps muddy and dead. This is something you must expect, and
must learn how to control.

As ever