Attributes such as Graphic Layer Recommended Display CIELab Value (0070,0401) consist of three unsigned short values:
An L value linearly scaled to 16 bits, such that 0x0000 corresponds to an L of 0.0, and 0xFFFF corresponds to an L of 100.0.
An a* then a b* value, each linearly scaled to 16 bits and offset to an unsigned range, such that 0x0000 corresponds to an a* or b* of -128.0, 0x8080 corresponds to an a* or b* of 0.0 and 0xFFFF corresponds to an a* or b* of 127.0
Note: This is the same form of encoding as used for the PCS in ICC Profiles.