.odt to epub heading format not maintained

I want to use headings that have a white font with dark background. When I use an online epub converter (the one in Writer doesn’t maintain links… if fact no converter I’ve yet used does a perfect job !), the heading number is the correct colour, but the white font is partially coloured with whatever background colour used.

I’ve not used ‘transparency’ with either font or background (paragraph - area).

Is there any way to prevent this change?

Please upload an ODF type sample file here.

Attached is part of the early book.

https://www.dropbox.com/s/5t4822oao2n8o2b/test.odt?dl=0

The white font on dark background fails but the number is correctly shown as white.

Most cross-refs apply to later sections so aren’t found but in 5.3.5 there’s a cross-ref to 5.2 and at the very end of the document is a figure that is cross-referenced from the text.

The Writer epub converter fails to do any links but some (eg. Convert any file, save as PDF, Word, HTML, CSV, JPG, HTML, ODS, BMP, PNG, SVG, TIFF, XPS and more. Immediate download, 100% Free Online) connect the TOC to headings and link my ‘house’ symbol back to the book marked ‘Contents’.