After formattting data points (changing colors) in a calc graph is not shown in Legend. see attached picture.
(Edit: activated screenshot -AK)
To return to normal, you must Reset Data Point. Then, to change color in legend and chart, you must choose Format Data Series…, not Format Data Point….
Tested with LibreOffice 6.4.7.2 (x86); OS: Windows 6.1.
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