# Changing the style of In[]:= and Out[]= and font of input and output cells

Just upgraded from V9 to V11 and the style for the cell labels In[xx]:= and Out[xx]= has changed. In addition, the default font for inputs and outputs have also changed. For continuity reasons, I would like to create a stylesheet that I can set as my default in V11 based on the styles of V9. My questions are 1)Is there an easy way to find what these styles were? If I can find that out, how does one change the In/Out cell label styles? I see CellLabelStyle in the style inspector but no option to enter or change there or in the page where we can create new stylesheet. Thank you.

To change your cell label styles at a notebook level, go to Format > Edit Stylesheet. Then in your stylesheet enter exactly CellLabel in the 'Enter a style name' input field. This will then allow you to apply all the usual formatting options to cell labels.
Alternatively, you can use the Option Inspector. Open the Option Inspector and change the first dropdown (Show option values) to 'Global Preferences'. Then search for CellLabelStyle. Click inside it's value and you can type in a new style. This new style can either be an inbuilt style (e.g. "Text", "Section"), or it can be a custom set of inputs (e.g. {Italic, 12, RGBColor[{1, 0, 0}]}.