Today Blogger has introduced two new “transparent” navbars – “Transparent Light” and “Transparent Dark.” To quote a few lines from the post:
These new color schemes take advantage of the ability of modern browsers to render transparency (a technique known to web designers as “alpha blending”). This allows the navbar background to blend together with your blog’s background color and pattern. The “Transparent Light” color scheme has a semi-transparent white background, producing subtle pastel colors, while the background of “Transparent Dark” is a semi-transparent black that produces a shaded look.
And also, as it was already observed Blogger has simplified and slimmed down the look of all the navbars, so as to harmonize with the aesthetics of your blog.