To change the Windows theme and colors under Windows 7
Step 1: Right-click somewhere on your desktop.
Step 2: Select Personalize from the context menu.
Step 3: In the Personalization window, scroll through the Change the visuals... pane and chose the theme that suits you best. You can see the desktop theme changing when you click on a theme.
Note: When you scroll down the pane, you will find the basic themes and high contrast themes, which have different color settings like white on black or yellow on blue, etc.
Step 4: At the bottom of the window, click Windows Colors.
Step 5: In the Window Color and Appearance window, select the item for which you want to change the color from the Item dropdown menu.
Step 6: Select the desired color from the Color dropdown menu.
Step 7: At the bottom right of the window, click Apply to see your changes.
Step 8: Click OK to save the changes and close the window.
Step 9: Press Alt+F4 on your keyboard to close the Personalization window.
To change the the Windows theme and colors under Windows 10
Step 2: Select Personalize from the context menu.
Step 3: In the Personalization window, select Themes from the left side navigation bar.
Note: When you scroll down the pane, under Related Settings, you will find a link to High contrast settings, which have different color settings like white on black or yellow on blue, etc.
Step 4: Scroll down to Change Theme and chose the theme that suits you best. You can see the desktop theme changing when you click on a theme.
Step 5: In the left side navigation pane, select Colors.
Step 6: In the Colors window, chose between Light, Dark, and Custom from the Choose your color dropdown menu.
Step 7: Click the radio button Light or Dark under Chose your default windows mode.
Step 8: You can Choose your accent color by selecting the desired color.
Step 9: Under Show accent color on the following surfaces, you can select accent color for Start, taskbar and action center and/or Title bars and window borders.
Step 10: Press Alt+F4 on your keyboard to close the window.
