KD27, KD28 & KD29
The KD27 and KD28 table lamp was designed by Joe Colombo in 1967 for Kartell, a company that makes and sells plastic contemporary furniture. KD27 actually refers to the chrome/metal version, while KD28 refers to all other lamps in plastic (white or colored).
KD28 came in several colors. Most of the available colors are listed on the picture above. On the left, you will find 2 of the 3 colors of the first series of KD28 (black, white, it lacks the red color). You can recognize the first series by the metal soquet under the globe. Other colors include green, brown, red, lime green, yellow, purple, black, orange and white. Lime green, yellow and purple were sold in Australia. On the picture only 1 color is missing, a "latte beige/café au lait".
Next to KD27 and KD28, Joe Colombo also designed the KD29. The design is very different compared to KD27 and KD28. Nevertheless, many people tend to mix up all the models. I understand the confusion :) On the picture above you can find a clear overview. From left to right: KD27, KD29 and KD28
The KD29 is also available in a range of colors: green, brown, red, yellow, purple, black, orange, white, ...
Putting a price tag on these lamps is not that easy. The color is very important if you want to determine the price. A white KD28 is the most common version and you should be able to find one around 150€. Prices can go up easily to a couple of hundred euro if you prefer another color. KD29 is also somewhat harder to find. A start price for this particular lamp is also situated around 150€-200€.
Source pictures: Teddy and Furniture Love