Based on the answer in this link, Inno Setup how to change the font color or style of label on TInputFileWizardPage
This is the code to change the font style,
PageFileSelect.PromptLabels[0].Font.Color := clRed;
PageFileSelect.PromptLabels[0].Font.Style := [fsBold, fsItalic];
But how to change the font name of the entire installer dialogs and controls in one go?