XF 2.2 Show custom fields

[Robert9]

I have field colors: red, blue, green, checkboxed;
Output in thread like:

colors: red, blue


I try to show these values somewhere else and use:

                <xf:macro name="custom_field_value"
                          template="custom_fields_macros"
                          arg-definition="{$fieldDefinition}"
                          arg-value="{$set.{$fieldDefinition.field_id}}" />

Result is

colors:

1. red
2. blue

How can I tell the macro to produce a comma-list and no ol/li?