The ornamental design for the paint color sampling display, as shown and described.
FIG. 1 is a front perspective view of a paint color sampling display with multiple sheets; and,
FIG. 2 is a right side plan view of the display of FIG. 1.
The components of the display shown in broken lines are for illustrative purposes only and form no part of the claimed design. Further, the vertical and diagonal hatching shown in broken lines is included for the purpose of illustrating color contrasts that form no part of the claimed design.