Bug with object colours

When selecting an object (a rectangle for example), and apply a colour to it, IF, between the last time you used that object and set its colour "as default for rectangle", you have used another object (drawn a trend line for example) but in a different colour, it automatically sets that latest colour as the default colour for the other object, so for example if I like a nice, almost transparent grey rectangle, but use quite bright trend lines, the next time I go to draw a rectangle, it is bright, not transparent and of the same colour used for the trend line I recently used - even though the default colour set for the rectangle is something totally different.

Please get this sorted - super frustrating! thanks :)