When Rick tries to pry a pipe loose to get water for himself and Minmei, he isn't wearing his scarf. After the pipe breaks and he gets up, his scarf reappears.
Rick is wearing a white scarf when he sees Minmei making tally marks on his racer. When he goes to explore and hits his head on the pipes, it changes to blue. After he returns to the racer, his scarf is white again.