This page has a test of field colors:

Test simple text values [edit section]

TextColorData
||text||color||
||yes||should be green||
||no||should be red||
||maybe||should be yellow||
||another line||should have no color||

text  ^	color  ^
yes	should be green
no	should be red
maybe	should be yellow
another line	should have no color

Query

Test color expressions on integers [edit section]

IntColorData
||integer||color||
||5||should be light yellow||
||10||should be yellow||
||20||should be yellow||
||50||no color||
||100||no color||
||600||should be red||
||1000||should be red||

integer  ^	color  ^
100	no color
50	no color
5	should be light yellow
1000	should be red
600	should be red
20	should be yellow
10	should be yellow

Query

Test some other expressions [edit section]

This tests use of 'in' and 'startswith' as well as empty lines in the colors list.

FruitData
||fruit||
||apple||
||banana||
||avacado||

fruit  ^

apple

avacado

banana

Query

missing column 'color' in table