I dont know if I used the right terminology in the title but, i am trying to create a milestone graph - using an incremental y scale (going up in 1s) , dates along the x axis and the milestones plotted at 0.5, 1.5, 2.5, 3.5.....etc

Problem is I need to colour each point differently, for example missed milestones (dates in the past) as red, others in green , some amber, etc. I created a table with 3 columns, red, amber, green - there are dates for each point(0.5,1.5,2.5....) but you cant have a date against multiple points i.e if there is a date in the red column, there wont be one in the green column, instead it will be #n/a.

So, when I select the Red and the position columns i create a normal line graph, now i want to select the amber column and the position column , copy it and paste special over original graph as a new series, but this just seems to repeat all the points generated by selecting the red column. If i create a separate graph using amber and position then it looks as i expect with different points plotted to the red graph.

Any help appreciated!