I have a huge collection of freshwater pearls, in many sizes, shapes, and colors. I've been buying them for about 25 years, online and from vendors at bead shows.

It is almost impossible to find a rich pink color, or a medium blue color.

Most "pink" pearls are either lovely shades of pale peach or pale mauve, or smallish (usually 6mm) and dyed a vivid, shocking pink color.

Same with blue. They're either a very dark cobalt blue, a very pale blue, or a medium grayish-blue.

Come to think of it, most vintage "purple" glass beads are actually a muddly kind of purple, too.

Is it chemical?? (Or personal????) :-D