Thank you for taking the time to report this bug and help make Ubuntu better. I have re-assigned this from update-manager to gnome-icon-theme, as that is the package which contains the default update-notifier icons for the Ubuntu Human theme. However, as already pointed out, from the GNOME Human Interface Guidelines:
"However, color should always be regarded as a useful addition to your design, not as a necessity. Never depend upon colors alone to display important information, and keep in mind that if colors cannot be perceived correctly (for example, the user has an 8-bit system, or is color-blind), your application should still be usable."
Therefore, I'm closing this bug as Invalid. Feel free to report any further bugs you might find.
Thank you for taking the time to report this bug and help make Ubuntu better. I have re-assigned this from update-manager to gnome-icon-theme, as that is the package which contains the default update-notifier icons for the Ubuntu Human theme. However, as already pointed out, from the GNOME Human Interface Guidelines:
"However, color should always be regarded as a useful addition to your design, not as a necessity. Never depend upon colors alone to display important information, and keep in mind that if colors cannot be perceived correctly (for example, the user has an 8-bit system, or is color-blind), your application should still be usable."
Therefore, I'm closing this bug as Invalid. Feel free to report any further bugs you might find.
Thanks