The problem is not blue parts of the picture, but overall level of blue light, which is coming mostly from white parts of webpages. In particular, the dark blue

The problem is not blue parts of the picture, but overall level of blue light, which is coming mostly from white parts of webpages. In particular, the dark blue parts of your page have the blue channel at less than 1/10 as intense as the blue channel in the white parts of your page (remember, the sRGB values are gamma-adjusted). It’s better to make your design look good (I recommend lots of lightness contrast especially for text, and nothing too outrageously colorful), and leave minimizing blue light exposure to the user/browser/OS.