Hex Colors: Numeric Representation for "Transparent"

Hex colors: Numeric representation for transparent ?

Transparency is a property outside the color itself, and it's also known as alpha component. You can't code transparency as pure RGB (which stands for red-green-blue channels), but you can use the RGBA notation, in which you define the color + alpha channel together:

color: rgba(255, 0, 0, 0.5); /* red at 50% opacity */

If you want "transparent", just set the last number to 0, regardless of the color. All of the following result in "transparent" even though the color part is set to 100% red, green and blue respectively:

color: rgba(255, 0, 0, 0); /* transparent */
color: rgba(0, 255, 0, 0); /* transparent */
color: rgba(0, 0, 255, 0); /* transparent */

There's also the HEXA notation (or RRGGBBAA) now supported on all major browsers, which is pretty much the same as RGBA but using hexadecimal notation instead of decimal:

color: #FF000080; /* red at 50% opacity */

Additionally, if you just want a transparent background, the simplest way to do it is:

background: transparent;

You can also play with opacity, although this might be a tad too much and have unwanted side effects in your case:

.half {
  opacity: 0.5;
  filter: alpha(opacity=50); /* needed to support IE, my sympathies if that's the case */
}

Transparent ARGB hex value

Transparency is controlled by the alpha channel (AA in #AARRGGBB). Maximal value (255 dec, FF hex) means fully opaque. Minimum value (0 dec, 00 hex) means fully transparent. Values in between are semi-transparent, i.e. the color is mixed with the background color.

To get a fully transparent color set the alpha to zero. RR, GG and BB are irrelevant in this case because no color will be visible. This means #00FFFFFF ("transparent White") is the same color as #00F0F8FF ("transparent AliceBlue").
To keep it simple one chooses black (#00000000) or white (#00FFFFFF) if the color does not matter.

In the table you linked to you'll find Transparent defined as #00FFFFFF.

Hex transparency in colors

Here's a correct table of percentages to hex values for opacity. E.g. for 50% white you'd use #80FFFFFF. To think in terms of transparency instead, flip the order of the percentages (more opaque = less transparent).

%	Hex
100%	FF
95%	F2
90%	E6
85%	D9
80%	CC
75%	BF
70%	B3
65%	A6
60%	99
55%	8C
50%	80
45%	73
40%	66
35%	59
30%	4D
25%	40
20%	33
15%	26
10%	1A
5%	0D
0%	00

What is the HEX code for Transparent color?

There is no such thing; transparency is done via another channel.

Opacity in Hex colors of CSS

The hex representation of colors supports the alpha channel to set opacity.

so, take any color in hex e.g. #ffffff and append 00 to ff (in hexadecimal representation) for opacity, i.e. #ffffff00 - #ffffffff

for your color: #78909c33

20% implies 33 in hex

Here is a demo

Reference: Hexadecimal notation

What is the color code for transparency in CSS?

how to make transparent elements with css:

CSS for IE:

filter: alpha(opacity = 52);

CSS for other browsers:

opacity:0.52;

Hex representation of a color with alpha channel?

In CSS 3, to quote from the spec, "there is no hexadecimal notation for an RGBA value" (see CSS Level 3 spec). Instead you can the use rgba() functional notation with decimals or percentages, e.g. rgba(255, 0, 0, 0.5) would be 50% transparent red. RGB channels are 0-255 or 0%-100%, alpha is 0-1.

In CSS Color Level 4, you can specify the alpha channel using the 7th and 8th characters of an 8 digit hex colour, or 4th character of a 4 digit hex colour (see CSS Color Module Level 4 spec*)

As of July 2022, >95% of users can be expected to understand the #RGBA format

It has been supported since:

Firefox 49, released Sept 2016 (Mozilla bug 567283).
Safari 10, released Sept 2016.
Chrome 62, released Oct 2017. For earlier versions you could enable experimental web features to use this syntax. See Chromium Issue 618472 and Webkit bug 150853.
Opera 52, released March 2018 (or Opera 39 when experimental web features are enabled).
Edge 79, released Jan 2020 (the first version of Edge based on Chromium)
Samsung Internet 8.2, released Dec 2018
Android P (your app must target Android P or newer)

It is not supported in:

IE
Original Edge (version numbers up to and including 18)
Opera Mini
UC Browser

Up to date browser support information is available on CanIUse.com

Add opacity to hex representation of color

8 digit hexadecimal color notation in CSS has the following format:

#RRGGBBAA

RR - red
GG - green
BB - blue
AA - alpha

You should use:

#EB575726 (for your 15% red)

Hex Colors: Numeric Representation for "Transparent"