White makes the relationships between pieces easier to notice. Maje UAE's White Capsule Collection brings the palette together, leaving you to play with the outline, overlap and detail. A shirt gives you a useful point of comparison when deciding how two layers should meet. Look at the actual tones together rather than expecting every white to be identical.
A belt can draw a clearer line through the outfit if you want definition. Or leave the silhouette uninterrupted and let a smaller detail become the focus. The capsule provides a colour direction, while your own proportions and combinations give the wardrobe its personality.