This page consists of screenshots from the Captcha Setup – Captcha Type Screen in Captcha Booster WordPress Plugin.
This gives an idea about how to configure Captcha Settings. First of all, you would need to choose Captcha Type. You would need to choose between “Text Captcha” or “Logical Captcha”.
If you have chosen Text Captcha, you can customize the styling of Text Captcha by settings its Colors, Width, Font, Noise etc.
In case of Logical Captcha, you would need to choose between different Mathematical Operations available for Logical Captcha.