While filing chips, I needed to pick the best of two Fremont, $1 CIC chips. While they looked identical and fit the TCR description for V2557, there was a very slight difference in the shade of purple. Under a blavk light (UV) there is a significant difference. The purple of one remains pruple under the black light and the other illuminates as blue.

Courtesy of the MOGH's ChipGuide, this is V2557:

Jim