Our recent release of ShinobiCharts v2.7.0 included an update that allows for individually styled data points in a column series. See this blog post for an intro to this new feature - http://bit.ly/1q9SS43
In order to change the width of columns, the properties interSeriesPadding and interSeriesSetPadding may be of interest to you. These control the padding between (sets of) series which in the case of a column series influences the amount of space available for the columns to take.
Let me know how you get on with your charts/app