Machin Postage Stamps 3

I've done some investigation into Machin stamp designs that take into account colour vision deficiency (CVD). In particular, I looked at CVD-safe colour schemes and visual representation of numerals for the denominations. See those three web pages for more details.

The numeral scheme I finally came up with (after a lot of experimentation) is as follows:

The symbols have the following properties:

1. The number of small dots is the value of the digit.
2. Each has a high-contrast, CVD-safe colour (from the 'Chilliant Pale/Deep 19' palette).
3. The outlines are distinct.
4. They all fit within a circle the size of the grey ring zero.

For dark backgrounds, simply switch the pale/deep pairings:

The names I've ascribed to each of the symbols are:

• 0: grey ring
• 1: slate circle
• 2: brown oval
• 3: purple triangle
• 4: cyan cross
• 5: green bowtie
• 6: pink star
• 7: blue heptagon
• 8: orange square
• 9: mint lozenge