### Instruction:

Extract the cause and effect entities from the following sentence:
A valid NRF color code will be assigned to the GTIN when all trade items are of the same color in the prepack; otherwise, the NRF color code 999- assorted prepacks whether the prepack is assorted by size only, color only, or both size and color

### Assistant:

VARIABLE: the NRF color code 999- assorted
CONDITION: prepacks whether the prepack is assorted by size only, color only, or both size and color
KEYWORD: when
NEGATION: otherwise
EFFECT_1: A valid NRF color code will be assigned to the GTIN
CAUSE_1: all trade items are of the same color in the prepack
EFFECT_2: the NRF color code 999- assorted prepacks whether the prepack is assorted by size only, color only, or both size and color

