In Chart, how can I choose colors for the axes?

I would like to create simple, math-like plots to be put into a pdf file. However the pdf file makes all the default axes colors gray, and they do not print well. I can find no way in Chart to control the color and thickness of the axes. Same problem with the data points.

Thank you. Your answer was most informative. Would you be good enough to consider two associated problems. 1) when I paste the finished chart into a Writer file, the data does not paste correctly. The rest of the chart (axes, colors, etc.) paste correctly.
2.) Is it possible to change a data point from Edit, or must one start over again with a new chart?

Sorry, I just noticed you asked more questions in the comment. Better to post a new question in the forum to have more visibility. 1) I tried this and the data for the chart will show in the data table of the chart. 2). If the data is in the chart data table you can change it from edit mode of the chart. Double click the chart to put in edit mode. If the chart is using a data range as it would in calc, then change the value of the calc cell and the chart should update.

Double click on the chart to change to edit mode.

Then use the X-Axis and Y-Axis options, the third and fourth icons from the right to set the axis colors.

For the data points, use the drop down list to select a data series, then select format selection using the icon to the right of the selection list. Under the “Line” tab you can choose the icon for the marker and set its size and color etc.