Colour change of sequin pattern

[CatalinM]

Hello!

I'm currently stuck on editing a sequin pattern background by changing the overall colours to some very specific colours. As it stands the overall colour is green but I want to change it to 8 different "global" colours. I'm trying to come up with an easily editable system in which I can edit the colours.

I've messed around with various colour levels editing every channel, curves, gradient map and channel mixer. The problem is that when applying these adjustments, the colour variety and depth of colour disappears in the tests I've done. I end up losing the 3 colours pink, lime and green diferentiation and it becomes more monotone. I've done some experiments with channel mixer and that seemed to work in some ocassions. Having said that I'm kinda looking for a system where I can maintain the 3 colour differentiation and expand the colour palette.

Anyone have some ideas that might help me to accomplish this?

Thanks in advance!
Catalin

 

[Peano]

It can be done by creating several layer masks to isolate the colors you want to change and the ones you want to preserve. One way is with the Calculations command (Image > Calculations). That's a moderately advanced tool, so if you aren't familiar with it, you'll need to look up some tutorials and go into learning mode. You might also try the Select > Color Range tool to isolate the greens or yellows. Here are two examples of what the resulting masks might look like. The one on the left reveals only the pinks; the one on the right hides the pinks.

 

[thebestcpu]

Hi @CatalinM
There are many variables in your project and not clear exactly what you want to control. e.g. you want to control 8 global colors yet do you need to control the positioning of those colors (a bit more complex). So I am going to make some simplifying assumptions. That being that you want the pattern you see and that you want independently control colors (e.g. Hue, Sat, Brightness) to 8 different values. I am also going to assume that you do not need the very subtle background pattern (within each circle) to be controlled separately and you want those colors to track as you have set the global colors. If you need more control then that please clarify as the solution for you to consider below does not cover those other types of variation.

The first step is that I want to be able to isolate the different colors. There are various approaches that could be used (e.g. as @Peano has descirbed) and I show another.
First i turned the Layer into a Smart Object so adjustments can be edited later if desired. Second I am going to turn the colors into their equivalent B&W luminosity values. I am doing this by applying a Layer Style with the Color Overly checked and the parameter settings is that the color can be any pure grayscale value yet the blend must be color. This does the desired conversion.

Here is the image right before applying that color Style


Here is the resulting image after applyng the Layer Style. I also show the Layer stack and the histogram. Note that the Luminosity range does not cover the entire area from black to white (to be fixed in next step)




To spread that out I apply a Curves adjustment Layer and change the black and white points and as well to even out the histogram, I applied a brightening at the high end as shown below.



Now to limit this to just 8 levels, I apply a Posterization Adjustment Layer with the value set to 8:



Now I have the pattern isolated to 8 unique gray levels across the entire image. So you might say, wait, I need color. Well that's the next step.
What we now apply is a Gradient Map adjustment Layer which turn grayscale into a color. I suggest using the rainbow spectrum map that has 7 colors as I have shown:. I have opened the gradient editor so you can see all of the settings. (Note it is seven colors yet with editing the color map you can change it to 8, I just wanted to start with an easy example where you initially don't have to edit the gradient map and just use an existing gradient map)



Now you might say. How to I adjust the colors to whatever you want. That is simple done by editing the color to change the color of any of the color stops or even adding another color stop. The approach to do this is in the Adobe documentation and this is an example link on how to make adjustments:

https://helpx.adobe.com/photoshop/using/gradients.html#gradient-editor

Bottom line is that you can now indepently control the groups of colors to any color you desire.

Now there is another issue though. You also asked how do I differentiate the colors so they don't look mushed together. I will give a few pointers and leave it at that unless you end up with more questions

1) The eye sees contrast better than it sees colors. So you want adjacent colors to have a different color luminosity.

2) Using color theory on what colors look nice in the same image is also helpful

3) I you really want the chosen colors you can fake some higher contrast by selecting those colors, ceate a Layer Mask, and then set a color style to place a contrasting stroke around the color (eg black) or a drop shadow around those particular colors.

4) You can just try a variety of already supplied gradient map presets to see what they generate for you.

Hope this gives you some approaches to consider.
John Wheeler

 

[CatalinM]

Hi @thebestcpu and @Peano

Firstly thank you so much for answering this thread. These are both really viable solutions and based on both of your assumptions this is exactly what I was looking for!
Thank you for the elaborate explanations. Wasn't 100% how to tackle it as was playng around with Channel Mixer and although it was giving some reasonable results it definitely was guess work and required a lot of experimentation to achieve the desired result.

Hope you have a fantastic week ahead!

Best,
Catalin