In regards to your first question, you can change the colors of each column by changing the style of the trends. Under the plots property, you will find the trends property where you will create a trend for each series. In the trend you create, you can specify the series to use and column for each pen/trend. You will then specify the key to the corresponding trend you want to control and change the color.
In regards to your second question, you can add an axes under the plots property that all of your trends use. Here is a link to our user manual regarding the Time Series Chart and its properties for more information. https://docs.inductiveautomation.com/display/DOC81/Perspective+-+Time+Series+Chart
Here is an example image from another forum post with the link to the post as well.