The icons show how quickly the particular field can be searched.
From FileMaker Help:
"A green icon indicates that the field is searchable. A yellow icon indicates that the field is searchable, but the search might take longer than fields with the green icon..."
The "Lollipop" is actually a magnifying glass.
Yellow badged fields are typically either fields from a related table or unstored calculation fields--both of which will result in slower search and sort performance if criteria is used that references that field.
Fran -- can you tell me where you found that information in FM Help? I tried a variety of searches using "field" and "color" and even "lollipop" and couldn't find anything.
Phil -- I couldn't find any pattern in the fields with yellow ... until I knew what I was looking for. I thought some yellow and green fields were defined identically, then I looked deeper and found that the indexing options were different.
Exactly. The keyword to look up in help is "badge".