It would be useful to have <ahid> entries with a different color, so it is easy to identify which texts are hidden in the help viewer.
Is that really a problem? Not that I'm against giving <ahid> a different color, but there are other problems with higher priority.
If all you see on the screen is white background text and yellow background fields, being able to see what fields are what is quite helpful, so really this would be useful for other tags as well. Similar to us having black bold for emphasis and purple bold for menu items, it would make it easy to identify features by their colors. Definitely not the highest priority, but a huge win for readability.
Helpauthoring extension is deprecated. closing wontfix.