I put together JQL queries to indicate a board card colors such that

Red – over 20 calendar days since this item was moved into this stage (note the issue could bounce around, between stages and this will turn red if the original time going into this stage was over 20 calendar days ago)
Yellow - over 10 calendar days since this item was moved into this stage
Green – less than 10 calendar days since this item was moved into this stage

Here is a screen shot that shows my queries:

Being able to use indicators on our KANBAN board, such as color cards to to visually show items that are starting to become or have been stagnant makes the boards much more usable & informative. However, this use of color cards makes the page extremely slow to load. Clicking on any story for a detailed view results in a long pause for the end user as the page loads again. On my team users do not want to work with this view, despite having it display useful information. Can an alternative solution be provided or can this solution be made more efficient on the backend?