Activate the command: 
Application Menu 
Options Sketching tab, or 
Tools Options Application Options Sketching tab.
Geometry Section
The Geometry section of the Sketching tab will allow you to select the colors of construction nodes (construction vertices, Construction Node Color) and construction objects (Geometry Color).
However, the color of construction objects depends on the status of the check box Color of construction objects follows View: Color By. When activated, the color of the construction objects shows the part, surface, or layer properties of the object, as set by the ViewAppearanceColor By menu. (Switching the Selection: Select to part or surface also changes the View: Color By.) When not activated, the color of the construction objects uses the color set in the Geometry Color.
If the Add Lines defaults to construction lines on new file open check box is activated, new lines will be added as construction lines by default. If this check box is deactivated, new lines will be added as regular lines.
Grid Section
The Grid section will allow you to control the spacing of the grid lines along the local X and Y axes. You can also control the color of the grid lines.
Other Input
The Moment of Inertia Divisions input is used when calculating the area properties of 2D sketches. The number entered is used to split the height of the sketch into rectangular strips which are then integrated. See the paragraph Calculating the Properties of a Sketched Region on the page Meshing Overview: Creating and Modifying Geometry in the FEA Editor: Drawing Planes for details on the area properties calculation.