src/main/java/com/basistech/tclre/ColorMap.java
short pseudocolor() {
        short co = newcolor();
        ColorDesc cd = colorDescs.get(co);
        cd.setNChars(1);
        cd.markPseudo();
        return co;
    }
short pseudocolor() {
        short co = newcolor();
        ColorDesc cd = colorDescs.get(co);
        cd.setNChars(1);
        cd.markPseudo();
        return co;
    }
pseudocolor - allocate a false color to be managed by other means.

@return a color, otherwise unused.