For accessibility options - a way for users to customise their own view's colours, font size and colour, and similar options. Just a simple menu for options like "Minimum font size", "Default font colour", "Background colour" that applies site-wide would be ideal - nothing too complex to navigate to suit users of varying computer literacy, but something that goes further than just the font size settings of browsers like Edge and means browser extensions aren't required. Could be placed as an option when you click on your icon, like there can currently be the Update Contact Details and Delegation options, or as a "Settings" option to add under System Admin - Self Service Portal - Self Service Portal My Options.

I know there are options with creating different Skins but doing this for every possible colour scheme that somebody may want would be a lot of unnecessary work for analysts to configure.

Marked as self service portal but would be beneficial across other interfaces too if possible to implement.