There are many different blog subscribe widget plugins in WordPress Plugin’s Repository. This tutorial is about a free WordPress widget plugin that lets you add a subscribe widget in your website‘s widget area with a color picker to change its color scheme as per your website‘s theme.
Install and activate WordPress Multicolor Subscribe Widget. After activation visit your WordPress admin area Dashboard -> Appearance -> Widgets and drag its widget to you sidebar. Widget configuration allows you to set custom Title and Description, Your Feedburner ID, global color scheme, foreground color, subscription box and go button text and width in px or % etc.