I could have sworn that some standard or other required that Below-the-Hook Devices be yellow.
But I just looked in ASME B30.20 and ASME BTH-1 and can't find any reference to colour...
Is there really no colour requirement for below-the-hook devices?
Most of them are, in fact, yellow. So...
FYI, the 3rd Edition of CISC's Crane Supporting Steel Structures Design Guide is available for purchase at CISC website here:
https://www.cisc-icca.ca/product/crane-supporting-steel-structures-design-guide-third-edition/
Also note supplement here...