In charts which allow you to view multiple circuits simultaneously (such as the Profile Chart) the colour of the profile lines displayed attempts to match the correct colours of the three phases.
For the first three items selected belonging to different phases either Red, Yellow and Blue or the newer EU "unified colours" will be used. This happens regardless of the order in which you select the circuits.
If you select (for example) Amps L1, L2, L3 or kW L1, L2, L3 (in any order) then the phases should be displayed in the correct colours.
Once these colours have been allocated then we attempt to choose further colours based purely on how easily distinguishable they are when used in combination with the existing colours.
You can choose to use either the "Classic" (RYB) or "Unified" colours in Options & Edit Tariffs.