Here is the answer.....
Top half of cabinet paint color:
Keep black since it really makes you side art shine.
Bottom half of cabinet paint color:
Pick a dark blue shade (like your picture 4) in which you can also find matching T-molding (might need to buy the T-molding first and then match up the color as paint).
After painting is completed:
Add black T-molding to the bottom (dark-blue) half (like you show in picture 4) and then add the darker blue T-molding to the top half of your cabinet.
Note: If the blue T-molding does not match the blue paint, it probably will not look right, however, if it does match, then WOW what a cabinet design. Make sure you stick with the darker blue shade ranges for T-molding since if you do not (and pick a light shade of blue), the blue T-molding placed over the "dark" black cabinet will "stick out" too much (ie: people will just notice the T-molding) . I like how picture 1 looks but I think the T-molding in that shade would stick out too much. Stick to a blue like in picture 4
PS: Make sure the dark blue you pick is not too dark as to be mistakened for black.....obviously.
How about posting a pic of my idea (basically your picture 4 with the same blue color used as T-molding on the top part) to get a better look at it, then take a re-vote. :>)
UncleT