It seems that colors within LRF files are specified by four bytes, in this order by ascending address:

w

transparency, with currently only two supported values: 0x00 for opaque, and 0xFF for transparent

R

red - 0x00 for no red, 0xFF for maximum red

G

green

B

blue

Note, w is omega, the last character of the Greek alphabet. The first letter of the Greek alphabet is alpha, and there is a widely-used color space that includes an alpha value: RGBA The alpha value (in the last byte of this encoding) is opacity, the complement of transparency--so it seems reasonable to use omega for transparency. One can only speculate on why Sony decided to use transparency instead of the standard opacity, and why they put their omega at the start of the byte sequence instead of at the end.