When I look at a collection of photographs in a book or exhibition, I usually prefer that the color and BW be in separate groupings. In my opinion, keeping color and BW in their own groups makes it feel (in most cases, anyway) easier to see the images in each group without the jarring alternations of adjacent images that would otherwise result.
It might in some cases help to go beyond the color/BW groupings and consider the impact of grouping horizontal, vertical, and square images separately.
Perhaps the purpose of the photographs will matter -- assuming there is a purpose beyond our own delight in making the work -- and thus the audience’s preferences or needs. But without a clear audience preference/need (if any such audience homogenization is even possible), my approach is to organize photographs in whatever sequence best serves the work, without a counterproductive solicitation of other people's preferences (productive solicitation is another thing). And then the art of sequencing photographs comes up for discussion. It is an endless one.
