Kraiden

https://share.google/SGdegy9zSrJEzlMYY

ETA: Actually this could use a little explanation. That link is just a random brown that I selected, but your question was about a specific shade of red, so here's how to find the specific hex code:

Let's assume your primary red is FF0000, and your primary orange is FFA500

Open the tool, and enter the hex for the shade you're trying to match: 0F0000. You'll see that there are other options for colour selection, RGB, CMYK, HSV and HSL. We're interested in HSV

HSV is Hue, Saturation, Value. The last number, Value is what we're interested in. 6% in this case.

Now enter the primary color you want to match: FFA500. You'll notice that the only the first and last number of HSV are different. If you set the last number to what we found earlier, 6% you'll get an equivalent color and the hex code for it:

#0F0A00

madness. How am I supposed to know if 36 = 36 or 36 = 8?

Not op, but for me it was the fact that the supposedly ineffable word of God turned out to be pretty effible

It wasn't the first step towards losing faith, or even the last, but it was pretty troubling to a young me