PIT: Animated GIF images are colored differently when created from opaque PNG/JPG image frames

I am trying to create an animated GIF image from a set of opaque image frames. I am reading each and every image frame from a file and getting the image metadata also. After setting the animation properties such as disposal method, delayTime I am writing each frame to IOS by calling writeToSequence() alongwith the metadata duly converted to GIF format.

All the frames except the first one in the output image are colored differently and the original color of the frame what was passed is not being used.

This is reproducible only on the following PIT build:
java version "1.6.0-internal"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.6.0-internal-java2d_13_sep_2005_00_48-b00)
Java HotSpot(TM) Client VM (build 1.6.0-ea-b51, mixed mode)

This is reproducible on all platforms with the above PIT build.

I have attached a zip file containing the sample test and few image frames. Run it as follows:
java WriterTest <dir Name> where <dir Name> is the name of the dir containing the individual image frames.
A frame will be shown with all the independent image frames and the animated image. If the color of the animated GIF is different from the actual frames, the bug is reproduced.