Background
Especially on a crowded canvas, modified monomers are not that easy to find. Introducing marked monomers on canvas can more easily draw the attention of the user to them.

Requirement

• Every modified amino acid, sugar, base and phosphate on canvas (flex and snake modes) should be marked as modified (see mockup).

Only amino acids, sugars, phosphates and bases can be considered modified. That means that there is no need for marking CHEMs, (unsplit) nucleotides, and unresolved nucleotides.
The list of non-modified amino acids can be found here: #5629, and the list of non-modified bases, sugars and phosphates here: #3734

UX