You need to add the strictMinMax property, this question has come up a lot in the forums. I suggest you use the search and have a browse with amcharts/serial chart as the search item, you'll gain a lot of experience very quickly I assure you.
For the graphs themselves if you want individual colours for each datapoint split them up and use series-#- attributes rather than just points and values.
Enable the api menu item under administration -> edit menu -> Api Docs, turn it on and click save at the top.
The maSerialChart will be under components.