Default colours for drawn items

The “set as default for..” - ie on drawing a rectangle, trend line etc, just does not work. It just remembers the colour used for the last thing you drew. To try to explain better...

I draw rectangles and use trend lines a lot. If I draw a rectangle, I like it to be grey and to have much-reduced opacity. Yet the trend lines I like to be much more visible. I set the colour as “use these settings as default for rectangle” or whatever it is it says, but if since drawing the last rectangle I have (for example) drawn a trend line using a bold, different colour, it then draws the rectangle as a solid block in the previous colour used to draw the trend line, and vice versa! 
 

Please try to fix this. Set as default for rectangle, or for trend line, horizontal line, whatever it is, should mean default for that particular object.