How can I adjust these background colors so they are the same?

Question

I'm using a set of pictures in a colour-themed report. Please take a look at the pictures below. The theme colour is RGB{52,177,201}.

I would like to alter the images slightly, more specifically, alter the blue background and make it look more related to colour RGB{52,177,201}. Note that the width:height ratio should remain 2:1.

The reason for doing so, is to make the report look more consistent from the perspective of colouring.

Does anybody have a suggestion to how to approach the problem? Is there a simple way to achieve this.

As of now, I'm starting to become familiar with adobe Illustrator. However, every advice/help is much appreciated.

EDIT: I would like to mention that the first picture meets already a 'fitting' colouring background. Secondly, I am not intending to remove the background, rather changing the background colouring.

Greetings,

Nadia

ETA from comments

What I have tried so far, is making use of tints and matching the color with swatches. This was all done in adobe Illustrator. However, this didn't give me a satisfactory result. The reason why I added photoshop, is that I presumed that the problem might be better addressed in Photoshop, as this is a pixelated image. For now, I have little to no experience in Photoshop. Nevertheless, I am willing to start photoshop if adobe illustrator is not sufficient.

The images are PNGs. I am not intending to remove the background, rather making it more matching with the first image. From my experience, removing backgrounds does not give the desired results. The contrast between the image and background became too big. Of course, could be due to my limited skillset. Nevertheless, the main issue is altering the blue-colour. Not removing.

Answer 1

Unfortunately only one of your images can be fixed easily:

It's the last one. There the background is nearly right, only a minor adjustments to blue is needed (except if the medical tool must stay intact, then you need a selection or mask like in other images)

They need an adjustment layer, I think Hue&Saturation with Colorize=ON is the right one. That layer needs a mask. To create it you must draw a precise clipping path just like you would do when you want to make high precision background removals.

You must use Colorize, because there's not enough room for hue, saturation and brightness adjustment, the noise will jump up

I guess you must adjust the colors of some blue items too to keep them visible against the theme background.

ADD: I tried the masked Hue&Saturation method to your PNG, which was free from JPG noise. The paper guys were easily (due the lack of the noise) selectable by color + a minor help with the polygonal lasso, but the stetoscope needed a clipping path. Actually I removed the background, as the duplicate voters obviously could predict.

The version without a background can be seen in the layers panel. The layer mask appeared to the adjustment layer by selecting the emptiness of the background free layer and inserting a layer mask to the adjustment layer. There's a snippet of the reference image as the top layer for adjusting the colorization. It was done subjectively because the reference has a gradient. I think the colorization is acceptable.

I guess the paper guys need something. I would make them a little better visible (=darker, a hue shift away from the background), like this:

NOT ASKED: For curiosity I checked if the blue colors could be printed in CMYK. The stetoscope has too bright blue and the modified paper guys have nearly the same. Color proofing showed that they will be flattened in CMYK printing to less saturated.

Photoshop can be set to warn of unprintable colors. Gamut warning shows the unprintable colors as grey:

The used print color profile was Euroscale Uncoated, which has much narrower color range than RGB displays. Your theme background seems to be printable as is.

Answer 2

• Add a background layer that is slightly bigger than your image
• Fill it with your theme color (this will be deleted, it's only for reference).

• Select your image only so that you don't modify your reference color.
• Go in Image > Adjustments > Replace color
• Select your background and increase the fuzziness to make sure you get everything

• Adjust the sliders at the bottom until you get close to your reference color.
• Rinse and repeat for all images!

It's a bit more straight forward but might introduce more noise compared to user287001's answer, hard to say without having the original image. Definitely keep an original copy of your images.

This one was fairly easy to fix but you may need to mask some items in your other images accordingly.