In nearly all respects, Red Bartlett Pears are virtually the same as their Yellow Bartlett counterparts, except of course in color.  Red Bartletts
add a beautiful contrast of color in fruit baskets and bowls, while providing the same familiar flavors and smooth textures of Yellow Bartletts.

For many, the Bartlett pear carries a true pyriform "pear shape;" a rounded bell on the bottom half of the fruit, then a definitive shoulder with a smaller neck or stem end. Bartletts are also extremely aromatic pears, and have that definitive "pear flavor." Just as Yellow Bartletts change color while ripening, so do Red Bartletts; changing from a dark red often with light vertical striping to become a bright red. Aside from color, there are no other differences between the two types of Bartlett pears. 
 

Pears are a good source of vitamin C and fiber.A medium sized pear, weighing about 166 grams, contains only 100 calories. Levulose, the sweetest of known natural sugars, is found to a greater extent in
fresh pears than any other fruit!  

Here is some very informative and complete Red Bartlett Pear links:
http://www.usapears.com/pbnw-redbartlett.cfm

http://www.rockymountainfruit.com/redbartlet.htm