Way 1: Turn High Contrast off via keyboard shortcut.
Press left Shift+left Alt+Print Screen to instantly turn it off.
Way 2: Turn High Contrast off via Settings menu
Step 1 go to desktop
Step 2 right click anywhere on clear area, the following menu should appear
Step 3 Click the "Personalise" button at the bottom of the menu, the following screen should appear
Step 5 Click the "High contrast settings" link, the following screen should appear
Step 6 Click on the" Choose a theme" drop down and select "None"
Step 7 Click "Apply" and exit out by clicking the "x" in the top right hand corner