You are faced with the task of creating a visualization of the aapl.csv dataset:

1. Read the dataset. Convert the "Date" column of df to datetime type, and set them as df indexes.
2. Initialize a line plot for the "Open" column values of the df. Set colormap to "gray".
3. Add a title to the plot. In this order, it should contain the "Open" column's max and min values.
4. Add labels on an axis: "Datetime" on the x-axis and "Price" on the y-axis.