On the silver W3BB0023, the bezel setting supplies most of the light. The W4BB0028 reverses that balance: the blue dial stays conspicuous even when the watch sits partly beneath a sleeve, while the stone-set edge catches light around it. Roman numerals retain the familiar Ballon Bleu reading rather than turning the colour change into a new dial layout.
Its rounded crown guard remains an important part of the profile. The blue front has the strongest effect from straight ahead, but the case curve softens that colour at the side. For a buyer comparing two 33mm stone-set Ballon Bleu watches, dial colour is the real decision; the pages do not need a generic quality claim to separate them.