The lamp above is the 12 inch Variegated Tan vase lamp, also know as the "Duo Tan" vase lamp. The inside of a clear glass vase is first painted with a tan paint, then fired to cure it. After the process is complete and the lamp cooled down the variegated finish along with the gold band around the bottom are hand applied. The variegated finish consists of a combination of colors applied to the outside of the vase. The colors used were simi liar to a flat paint and what more recently has become known as a "faux painting". The result was to give the vase a more dull finish with each lamp being a one of a kind paint scheme.
While this is lamp is also a 12 inch Variegated Tan vase lamp you can easily see there is quite a difference in the two. The link to both is simply the fact that the inner fired on color of both the lamp is indeed tan and they both have the gold band at the base. The variegated paint however is drastically different between the two lamps. The strange thing is that I have seen several of both paint schemes. Enough so that I'm not sure they should share the same designation. One lamp has a rather distinct dominant green color, while the other a more dominant black and brown color.
I cold understand this as just being the difference in the hand applied paint between two lamps, but like I said I have seen several examples of each color combination. After seeing enough of these variegated tan lamps it starts to become obvious that there were two distinct paint schemes used on them and each consisted of it's own dominant color scheme. One more green, the other more brown and black. If you try, you would probably be able to find examples matching both of the lamps above. Remember however, the link is that both share the tan paint on the inside of the vase.
If you are wondering how a lamp as ugly as this one could ever be popular with buyers, just remember it was one of the first colorful glass lamps manufactured by the Aladdin Mantle Lamp Company in 1930. Prior to that date the lamps were all metal.