HOW TO PLOT A LINE GRAPH WITH CORRECT VISUALIZATION OF SERIES?

Hello there friends, I have got a problem with the correct visualization of a lines graph, I have the data listed below:

THEN WHEN I CREATE A LINES GRAPH USING TASKRSRC.TARGET_QTY ON "X" AXIS, SUMA DE DATOS Y LOB ON "Y" AXIS AND TASK ID ON LEYEND FIELD I GOT THE FOLLOWING GRAPH:

THIS GRAPHIC IS OK IN FORM BUT I DONT LIKE EACH LINE HAVING  A DISTINCT COLOUR, I KNOW I CAN CHANGE COLOURS MANUALLY (MORE TIME SPENDING), SO I CREATED THE COLUM ACTV_CODE_ID, THIS COLUMN HAVE THE SAME NUMBER OR CODE FOR VARIUS ROWS SO I THOUGTH DOING THIS WAY THE CHART WILL DISPLAY WITH LESS COLOUR SERIES ( I CREATED THIS TO OBTAIN LESS SERIES COLOURS IN THIS COLUMN WITH THE SAME X Y DATA)

THEN WHEN I CREATE A LINES GRAPH USING TASKRSRC.TARGET_QTY ON "X" AXIS, SUMA DE DATOS Y LOB ON "Y" AXIS AND ACTV_CODE_ID ON LEYEND FIELD I GOT THE FOLLOWING WRONG GRAPH:

I THINK THE PROBLEM IS THE SOFTWARE IS NOT RECOGNIZING ALL THE COORDINATES AND I DONT KNOW HOW TO CORRECT THIS, IT MUST BE THE SAME FORM THE FIRST GRAPH SHOWED. 

GRETTINGS.