What is the hex code for 30% gray? How do you work the math?

Question

I know it's between #C0C0C0 (25%) and #969696 (40%), but I don't know what it is exactly.

What is the answer, and how do you do the math to figure this out?

Note: The color values mentioned above are taken from Office 2003. So, they definitely have the possibility of being incorrect.

Answer 1

The number #C0C0C0 is in hexadecimal (hex). This number consists of 3 two digit numbers next to each other. The 3 numbers can be in the range 0 to 255, giving a range or 256 for the 3 channels. In hex this range is from 00 to FF. The 3 channels are for the colours Red, Green and Blue respectively.

I will cheat, and use a paint program to find out the decimal equivalence to #C0C0C0, it is 192 192 192 with a space between the numbers for readability. The number C0 is for 192, therefore you have the amount of red is 192, the amount of green of 192, the amount of blue is 192.

To get the figure of C0 (192) as 25% gray, you multiply 256 by 25% and take this away from 256. This gives 192 as the figure. You then need to convert this back to C0 in hex.

As for 40%, you get 153.6, when converted to 154 it gives #9A9A9A in hex.
With #969696 you get the red, green, and blue values of 150, which is 40% of 250 not 256.

For 30% we get, 256 - 256 * 0.3 = 256 - 76.8 = 179.2
Rounding this, we get 179, and the hex code of #B3B3B3
If you would like to round up to 180, we get #B4B4B4

Answer 2

Gray Hex Code

Answer 3

30% gray is #4C4C4C.

It's easier to convert the number to decimal format to find out what 30% is.

FF = 15*16 + 15 = 255

255 * 30% = 76.5 ≈ 77

77 = 4Ch

Unless you're thinking of 70% which it looks like what your thinking of. In which case, the answer is #B3B3B3.