For memories’ sake / Lovell Films & Preservation Project present, a film by Ashley Maynor ; producer, Paul Harrill. (OCLC #651057604)
RDA 126.96.36.199 on Details of Colour Content describes recording “details of the presence of colour, tone, etc., in the content of an expression, and the specific colours, tones, etc., including black and white, present. Record details of colour content if considered important for identification or selection.” There was a specific rule for color of moving image, but it has been deleted in a revision to RDA.
The OLAC best practices guide for DVD and Blu-Ray gives more detailed examples, including the one used in the physical description of this video:
300 __ ǂa 1 videodisc (29 min.) : ǂb sound, color with black and white sequences ; ǂc 4 3/4 in.