There are a few ways to accomplish this with some being harder than others. Lets look at one that is perhaps the easiest.
Open the image in Gimp > Duplicate the layer in the layer dialog window (making sure that the new layer that you will be working on is above the original) > Use the Colorize Tool to pick a hue that you like (experiment with hue, saturation and lightness using the tool) > Set the Layer Mode to Screen
in the layer dialog window (This step should preserve some of the small background colors while changing the overall foreground colors) > Review your work and repeat process if needed or use the undo steps button.
Please see the below example:
I didn't know the exact hue that you were looking for, but this should serve as an example of what you can do.
I'm planning on sharing what I eventually come up with, and possibly in versions for Mint and Mint KDE, once I get them done.
Please take note that the original artist
of this image has it listed as All Rights Reserved
. Using this image for your own personal use should be just fine, but you should contact him/her before making any public release
of any derivative work that you conceive. This is normal protocol. Most people will normally allow this as long as it is an not for profit
project of their work.
Hope this helps!