Marco this is a great solution for me. Much appreciated!

@Kuba Podkalicki and @Marco Thiel gave excellent answers. I'd like to make a short note. When you would like to change the color you basically asking for a function mapping from existing RGB channels' values to new ones. The most general function that does it is ImageApply. Look through numerous examples there. You can apply function directly to the channels vector {R,G,B} or different or mixed functions of separate channels. My favorite example is selective-coloring or color-splashing. Imagine you have an image:

I will import it back in WL and convert everything to grayscale but the most striking red:

img = Import["https://wolfr.am/c6vProOq"];
ImageApply[If[#[[1]] > #[[2]] + #[[3]], #, ConstantArray[Mean[#], 3]] &, img]

Of course you can act on all channels simultaneously too, - and going back to summer:

ImageApply[RotateRight, img] 

Another neat way is color transfer, see docs:

pic = Import@
  "http://community.wolfram.com//c/portal/getImageAttachment?filename=\
multseg1-8combinedwithreflection250pixel.jpg&userId=167076";

Maybe it can be done quicker, don't know :)

Colorize[
   ColorConvert[pic, "GrayScale"], 
   ColorFunction -> (Blend[{Red, White}, #] &)
]