In the Table component, the backgroud color list enable to indicate keys for values color mapping.
does exist a specific key for “All other value”, or expression like “>1”
Using the Background Color List mappings each key can only hold a single value. Any other value (values not explicitly defined in the Key-to-Color mapping) will use the default color for the table.
If you want to change the background on the entire row you can use the Number-to-Color translation table located on the Background Color Mapping tab of the Table Customizer.
If it is imperative to only change the background in a given column then your best bet is the Extension Functions(introduced in 7.6.0), available under the Scripting menu on the table.