RGB Color Transparency - colors

Does a color transparency give us a new color? for example - If a color is made to be 50% opaque, would that make a new color or would it be just 50% transparent of original color?

No, the RGB values are the same. The transparency and the opacity don't change them.

Related

Is there a term for non-grayness of a color (where black and white would be non-gray)?

If the RGB space were rendered as a cube, white, black, red, green, blue, yellow, magenta, and cyan would be corners; gray would lie at the center of the cube.
Is there a name for colors on the surface of that cube?
In simple terms, non-grayness could be quantified (with r, g, and b from [0..1]) as
abs(max(r, g, b) - .5) / .5
Here, white, black, red, orange, etc. would have a "non-grayness" of 1.
A recent article in colour vision theory (an open-access version is available on bioRxiv) defined this concept as vividness.
It is based on the representation of colours in a colour solid, where each axis is one component of colour. In such solids, the origin is black and the opposite edge is white. For example, this is the colour solid of the CMYK colourspace, plotted in this StackOverflow question:
Vivid colours are colours on the surface of this colour solid, which is exactly what you are describing in your question:
We define a measure of colour vividness, such that points on the surface are maximally vivid and the ‘grey’ centre is minimally vivid.

How to implement a color contrast enriching algorithm? [duplicate]

This question already has answers here:
Determine font color based on background color
(22 answers)
Closed 2 years ago.
I am currently developing an App. In this App I get some RGB color code from the server, that I want to display.
As the color I get should be the background color of a Label, there is some text, that should be displayed above it. The user defining the color is completely free in choosing a color, so I am in need of finding an algorithm, where the text color of the label is somehow contrasted to the color I get from the webservice.
Problem explained in an example:
I choose black 0x000000 to be the textcolor. If the user defines a color like dark gray 0x111111, the text's visibility would be very bad.
In addition, I want the text color to be black or white in order to not over-color the app.
So how can I determine, if white or black is the better color for the textcolor, based on a RGB code I get from the server?
You just should calculate contrast ratio for user color with black and white, then choose the color with higher ratio.
Here is description for calculating relative color contrast from RGB.
Note that relative luminance of white is 1.0 and for black is 0.0, so (if you are considering only black and white) you can just check if relative luminance of user color is <0.5 then use white, and use black otherwise.

Why! 100% Cyan in CMYK is NOT rgb(0,255,255)? in Photoshop

I try to convert a solid cyan to RGB in photoshop. But I get confuse about the RGB values "rgb(0, 160, 233)".
Where can i find the formula or icc profile to calculate RGB values that like Photoshop.
There is not one conversion which is "right" - it depends on the colour profiles you are using.
For instance, it could be the case that your CMYK Cyan is outside of the sRGB colour space - in that case Photoshop tries to get as close as possible to the right colour, but it stays within the RGB-values that are possible for this profile. Don't wonder if other programs calculate other RGB-values.
But if you change to ProPhoto RGB colour space, it may be possible to match your Cyan much better, as this colour space is much larger. So, of course, the RGB values are different again.
For more information, see here: https://graphicdesign.stackexchange.com/questions/5138/why-are-colors-shifting-when-converting-from-cmyk-to-rgb-in-photoshop

Retain colour but change transparency in photoshop

How can I retain a specific colour of an object (or layer) but change the transparency?
I have 2 objects which I want to have a specific colour but currently the opacity is 100%. I need to maintain the current colours but with a opacity of 50%.
Obviously if I change the opacity the colours change (dependent on the background). I need to know how to get an original colour at 100% opacity to make my desired colour at 50% opacity.
Okay so couldn't find a specific way to do it with photoshop so I worked out the math based off the RGB values and came up with a formula to do the job.
For each colour channel I used this formula:
Colour value = Desired Colour + (Background Colour - Desired Colour)*(1-1/Desired Opacity)
eg. 30 = 120 + (255-120)*(1-1/0.6)
Obvious only values between 0-255 are applicable and you may need to round values. This also needs to be done 3 times for red, green and blue.

how to get rgb values in percentage in photoshop

how to get RGB values in percentage in photoshop.
and is cmyk percentage values are similar to RGB?
RGB and CMYK are different color modes.
RGB colors are screen colors. It is expressed in absolute values, usually in integer values from 0 to 255, representing the brightness on the screen. The exact range of values depends on the color depth of the image. The higher the value, the more light of that color is added, so the highest color is white.
CMYK colors are printing colors. They are used to represent the amount of ink used for a pixel. This is no absolute value, because it is merely a ratio between the color components. The higher the value, the darker it gets. 100% of each is (near) black, although real black is usually constructed by using 100% of K (key) and about 30% of each of the other components.
integer values from 0 to 255 are for 8 bit color, in the day of 16 or 32 bit color it would make sense to be able to view rgb as percentage values.
this is being added to Adobe lightroom currently does percentaes unless you're in the develop module, in soft proof mode

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