When creating your own experiments, you can use arbitrary colors by a 6-digit hex code representing the byte values or red, green and blue (see  for details), without a leading hash "#".
Alternatively, you can use the names of defined colors. Phyphox often uses orange (#ff7e22) as its default trademark color, but it also defines a palette of additional colors that work well on the typical dark background of phyphox. These are:
orange ff7e22 red fe005d magenta eb46f4 blue 39a2ff green 2bfb4c yellow edf668 white ffffff
weakorange ffc399 weakred ff7cac weakmagenta f6aafa weakblue 9dd1ff weakgreen a1fdaf weakyellow e7e09b weakwhite c4c4c4
The advantage of using these color (besides using intuitive names) is that phyphox can adapt them even for future functions. For example, a bright mode or an export function for printing is introduced, which requires colors to work on a bright (or even white) background. Yellow from the list above could automatically be replaced by a darker variation working well on the bright background.