I have to make a symbology based on a unique color value so I add a plus column to the attribute table with the number of color values. I went to the layer properties - style - data defined properties and trying to change the outline color, but it is so complicated. I have 5 different value numbers so if the value number is 2, it can be red, and so on... What codes should I use?
The map should look like this with different sizes and colors based on the unique value
Yes you can do it with fewer values, depending on the combinations you want of course. In the Data Defined Properties section, click on the curly E button to define an expression. When the Expression dialog box opens, you will probably want to define a conditional expression. Use the CASE ELSE option and create an expression something like this (for the Border color, say):
CASE
WHEN style_attribute=2 THEN '255,0,0'
WHEN style_attribute=3 THEN '0,255,0'
...
ELSE '0,0,0'
END
The last one is a catch-all to make everything else have a black border.
You can then define similar expressions for other style elements such as the size and so on. NOTE the 'Help' section in the Data Defined properties dialog. It will give you a hint as to how the THEN clause should be formatted (in this case 'r,g,b' - the alpha here is the default).
