How do I subtly show that an element in large collection of elements was recently changed?
I have a large collection of elements displayed in a calendar-like grid. These elements represent entities that can change over time, but many won't. The elements are rendered like cards, evoking a feeling of a of a cork board with 3x5 cards stamped into it in a neat grid, or a calendar with lots of sticky notes on it.
I want to be able to highlight those elements that have changed in the last 24 hours. I'd like it to be obvious if I'm looking for it, but not distracting or jarring if I don't care. I'm considering going about it in a few ways:
- A color, one that will stand out against the sea of white boxes. I'd prefer to avoid a background color, as those are currently reserved for significant issues with the card.
- A non-color icon or other indicator for the colorblind.
- Placing this indicator in such a way that it's easily scannable - if there are 50 or 100 of these on the screen, I'd like it to be relatively easy to see those recently changed.
Icons considered:
- Pencil - seems off, since this typically indicates that was ever modified, which isn't important here.
- Check - seems off, because it tends to indicate "things are ok" or "everything is good"
- Circle-clock - maybe?
What I don't need:
- Just because the element has been modified (e.g., a 'pencil' icon) doesn't meet my need, editing and changing these cards are an acceptable task and not important in working on this problem. Only the recent changes need to be highlighted. (e,g, How to show that an element has been previously modified might be incorporated in some respects, but I think isn't the full answer.)
Some additional context:
- The order of cards can change, and are significant.
- Columns represent days. Rows represent priority within that day.
- Cards can be dragged and dropped to re-order.
The application looks a lot like a Jira kanban view. (here's a generic image from an image search as an example):
What might be a good way of allowing these elements to sufficiently stand out, without being too jarring?