You need a totally colored figure and a non-white background (otherwise the glow won't be that noticeable). But if you want to try it with white background, OK, fine. You should have something like this:
Select all the color layers:
And press Ctrl + E, this way you will merge all the colors into one single layer:
Make a duplicate of that layer by right clicking it and select the option "Duplicate layer". You will get a window like that, write down whatever name you want and click OK:
Drag the layer on top of the lines layer:
Change the blending mode to "Hard Light" as seen in the picture:
Go to Filter - Blur - Gaussian Blur. A window will pop out, choose whatever amount you want.