To Control the Text Style in Dimensions

Click Home tabAnnotation panelDimension Style. Find
In the Dimension Style Manager, select the style you want to change. Click Modify.
In the Modify Dimension Style dialog box, Text tab, under Text Appearance, select a text style.
If the current text style does not have a fixed height, enter the height of dimension text in the Text Height box.
Under Tolerances, enter a height for tolerance values in the Scaling for Height box.
In the Offset from Dim Line box, enter a value for the gap around base dimension text.
Select a color from the Text Color box.
Click OK.
Click Close to exit the Dimension Style Manager.