36RCW#1, Primary Yellow
by default (1996) it is an opaque color pigment.
Today, 2009, we have eight transparent dual-toned yellow pigments.
 

Yellow is at the top of the Real Color Wheel, 'read red right'.
Yellow is one of the three pigment primary colors.
The color Brown is a dark yellow hue.
Mix either the translucent Burnt Umber,
( or the cheaper and less usefull opaque brown which some companies are now selling )
or a the transparent brown/side yellow pigment with
Ultramarine Blue (opposite) to make a dark neutral.
A neutral dark can be tinted to make a Neutral Gray by
adding the top-tone white or the under-tone's clear medium.

Bellini Lemon Yellow Lead Chromate, Opaque

Mussini Cadmium Yellow Lemon, Opaque

Indian Yellow Golden duel-toned

Old Holland Indian Yellow -Brown/side duel-toned

 

One company still makes an oil dual-toned transparent yellow.
Old Holland, Indian Yellow-Orange Lake Extra, Transparent, dual-tone.
*Since I made this page in 1997, other manufactures have started making their versions of Indian Yellow.
No other company is making Transparent Indian Yellow-Brown yet.
You should have the pair. 10/12/02