This is a political design. The use or lack of colour helps extenuate the point the creator wants to create. The use of flowers, as a severe contrast to violence and war, also shows the message of peace, not war. Powerful visuals in a simple way.
I love how this montage highlights all the important momuments with beautiful bright patterns that stand out from the black and white background. People probably see these buildings and monuments like this, just not with the patterns.
This is a very animated piece with a lot of motion and color. As you can see it is a photograph mixed with digital art. This picture reminds me of a piece of art found in the since that era was known for the pop vintage colors.