Rgb to Hex - Hex to RGB

RGB stands for Red(R), Green (G), Blue (B). RGB is a color model where these colors are combined to create other colors. RGB for White is 255, 255, 255. RGB for Black is 0, 0, 0.
All other colors are in between these two.

Hex code is hexadecimal representation of RGB code. It expresses the same color in hex format.
Hexadecimal system uses 0-9 , A-F to represent the binary digits. 255 is FF in hexadecimal and 0 is 0 in hexadecimal.
So white is FFFFFF in hexadecimal.

It is a more compact and shorter represenation of the color and uses fixed 6 digits unlike RGB that varies between 1 to 3 digits for each of R, G and B.

HSL : H - Hue, S - Saturation, L - Lightness. Hue means color (combination of Red, Blue and Green). Saturation refers to the intensity and purity of the color.
100% means the color or hue is pure not mixed with other shades, 0% means it's more of grey and not pure. Lightness is same as Brightness which is amount of white / black color added to it.
100% white is one end of lightness and 100% black is the other end representing 0 brightness.
Hue is value between 0 to 255 (0xFF), Saturation and Value are in %.

HSL : H - Hue, S - Saturation, V - Value. Hue means color (the combination of Red, Blue and Green).
Saturation refers to the intensity and purity of it. As saturation increases it tends towards white shades and 100% means the color is white.
Value is the brightness of a color. light color are also referred as tints and dark color are referred as shades. It does not go to white but from black to the chosen hue.
Hue is value between 0 to 255 (0xFF), Saturation and Value are in %.

HSB is hue, saturation and brightness. It is same as HSV.

HSB and HSV are same. HSB is Hue Saturation Brightness. HSL and HSB/HSV are different.

Hue is same in HSL and HSV but saturation and light/bright behavior is different in both. Saturation indicates intensity in both.
In HSL , they grey component increases and becomes max as 100% but it's not white. In HSV, 100% saturation becomes white.
The Lightness / Brightness in HSV goes all the way from black (0%) to white (100%). In HSV, it goes from black to selected hue.
So the range of % in saturation and lightness/brightness values vary.

These color models are mainly used in computer software like image processing/editing tools, image scraping , facial recognition, computer graphic applications.
RGB is a simple visual color model as perceived by the human eye.
HSV, HSL are used by computer systems to process color information with intensity, lightness and other parameters and create a visual model that matches that of human visual processing.

CMYK is another color model and industry standard for color printing. CMYK Stands for Cyan, Magenta, Yellow and Key(Black).

RGB - when all colors are combined, it is white in RGB and absence of color is black.
CMYK - when all colors are combined it is black and absence of color is white.
Screens, Televisions and monitors all use RGB color model. Wherever visual medium is based on transmitted 'light', RGB is preferred.
CMYK is mainly used in color printing.

The different colors are combined in various ways to produce new colors going from darkness to lightness.
It starts with Black which is rgb(0,0,0) and as the colors are added in different intensity, it produces new colors of increasing values
It finally becomes White which is ryb (255,255,255). RGB is an additive color system and creates illumining colors on screen using transmitted light.

It starts with White (bg such as paper) and then when subtractive colors are mixed with it, it becomes darker and darker till it is black.
CMYK is a subtractive color system where adding Cyan, Magenta and Yellow to white in equal measures makes it black.
Black is the 'K' part of CMYK also known as the key color. This is based on reflective light from a white medium.

Brightness is absolute value like 0%, 25%, 60%, 100% and it's independent of the observer.
Lightness is perceived view of the brightness. It depends on the observer.
Luminosity is the light emitted by an object. It depends on the surface area, object type and a calculated value.

Convert the red, green and blue color values from decimal to hex. Concatenate the 3 hex values of the red, green and blue together: RRGGBB.

Get the 2 left digits of the hex color code and convert to decimal value to get the red color level.
Get the 2 middle digits of the hex color code and convert to decimal value to get the green color level.
Get the 2 right digits of the hex color code and convert to decimal value to get the blue color level. And get 3 values that correspond to RGB values.