Hex colors got me spinning crazy

[Elmug]

Good people:

I picked a color for use with code directly using Lzarus and it was this color numba:

$00C4FFFF

This shows a yellow color, like post-it notes.

Now I tried to use a lighter yellow and using the web, picked a yellow color. I place it in the code and I get a light sky blue.

Now, I put the $00C4FFFF in a web app that generates color from hex number and I get a bluish color in the same vecinity, turquoise like.

I now got doubts on what's going on. Of course if I use only Lazarus numbers withing Lazarus all is OK.

But those numbers are not valid outside, or are offset? I thought HEX numbered colors were standard.

NOW I got this yellow number from Lazarus:
D9FFFF

and in the webpage generator this gives me a light turquoise again. As if the light cyan or turquoise and yellows are exchanged?


Thanks for any replies.

[Leledumbo]

I think instead of relying on the number you should use RGBToColor, endianness problem might cause the bytes to be swapped.

[Dick, from the internet]

Swap the first two digits and the last two digits and give it a try; D9FFFF  -->>  FFFFD9.

[User137]

Lets see that in detail: 00C4FFFF Divided in 4 parts
00: Not sure what exactly this is for...
C4: Intensity of Red
FF: Intensity of Green
FF: Intensity of Blue

You know that full yellow should be FFFF00, and full blue a 0000FF. So whereever you first got $00C4FFFF for yellow was not RGB, but BGR.

[fabienwang]

Lets see that in detail: 00C4FFFF Divided in 4 parts
00: Not sure what exactly this is for...
C4: Intensity of Red
FF: Intensity of Green
FF: Intensity of Blue

You know that full yellow should be FFFF00, and full blue a 0000FF. So whereever you first got $00C4FFFF for yellow was not RGB, but BGR.

00 is the alpha Intensity, which means the transparency of color.

[User137]

00 is the alpha Intensity, which means the transparency of color.

I suppose. It's just confusing when it's used in solid colors which don't support transparency. I take it's just a placeholder most of the time.

[Elmug]

Thanks for the great help, everyone.

I will just use and pick colors for Lazarus use using its own color picker from now on.

Since the color number was for use in a short code statement, I thought opening web pages which have color charts with hex were compatible with the Lazarus numbers.

I even thought maybe the first webpage I visited was wrong. But then I got the same differences in other webpages.

I still don't gather the reason for the difference, though.