Multiple Foreground/Background Colors or How do I Pallet?

I posted a question here (in full) along the same lines as yours 😉

https://community.adobe.com/t5/photoshop-ecosystem-ideas/how-can-i-have-more-than-two-colours-in-the-colour-selector-1st-2nd-plane/idi-p/14902014

I understand your request!

Personally, I'd like to be able to paint like a ‘rainbow pencil’. In other words, to be able to draw with a pencil (or brush) and change colour (without lifting the stylus).

And ONLY 2 colours do NOT suit me!
I need between ~ 4 and 5 colours!

The principle of the 1st/2nd colour plane is a good one. I'd ‘simply’ like the same principle, but with a number of colours to choose from (at least 4 to 5 - but why not many more...)

Is this possible?

EeveeonE83980361 wrote: “how do I get a pallet? Other than putting my colors on another layer, it feels way more convenient to have it on the UI.”

The Swatches panel (Window > Swatches) does most of what you asked. You can create a set of your own colors, arranged in any order you like, visible in the UI, and you can click any of your own swatches to change the current foreground or background color. The only thing you want that the Swatches panel doesn’t have is being able to apply the next color with a keyboard shortcut. Many people leave the Swatches panel open all the time, so they can just click the color preset they want to apply next.

If you aren’t already familiar with the Swatches panel, it’s definitely worth learning and mastering because it also appears in other Adobe applications.

The Color panel would probably be useful for you. All panels can be accessed under the Window menu.

If there are colors you use frequently, you can set up your own Swatches panel by adding and deleting colors in the panel. Then in the Swatches panel menu in the upper right corner you can choose to save your custom set of swatches.

You can easily create a script that will change the foreground color through an array of your colors and assign a shortcut key for that script. However the shortcut key can not be a letter like X.   Photoshop keyboard shortcut editor does  not support reassigning all of Photoshop shortcuts and assigned shortcuts must contain a Ctrl or CMD key as part or the shortcut.   F keys are also supported as shortcuts but an actions assigned the same key will override the shortcut F key.  Ctrl+X is the default shortcut for cut.  That most likely can be changes however  Ctrl+Alt+X would be a better choice for the foreground color switcher script.  You can use it  in combination with the X key switch the foreground to the background color then switch the foreground color the X Key will then switch between two of your colors. The D key will reset the swatches to BW.

A simple script like this will set random foreground and background colors:

app.foregroundColor.rgb.red = Math.random() * 255
app.foregroundColor.rgb.green = Math.random() * 255
app.foregroundColor.rgb.blue = Math.random() * 255
app.backgroundColor.rgb.red = Math.random() * 255
app.backgroundColor.rgb.green = Math.random() * 255
app.backgroundColor.rgb.blue = Math.random() * 255

Pressing X doesn't change color. It switches between foreground and background color. That's hugely useful in a number of different situations and changing this functionality is off the table. Not going to happen, ever.