In XML for ODT documents, it is not possible to define a font color directly on a table row, a table cell, or a paragraph that contain the text in the cell. You can only apply a style to those elements.
So the solution is to defined a named Paragraph Style for each font color you need in your table, and then changing the style of the paragraph (a text in cell is always in a paragraph) with a TBS field using parameter att
.
Example : [blk.my_style;att=text:p#table:style-name]
Unfortunately there is an additional difficulty: LibreOffice will save your custom style with an internal name. The name you give to it using the software is only a displayed name (an alias). So the solution is to look in the styles.xml
file for the internal name. Or you can wait for the next TBS version (3.11): it will have a feature for reading attributes in the template.