fix: hex8 to rgba

[savroff]

Problem

Currently Chroma::Color generates a wrong RGB from HEX8. Here is proof that #eb09b9c4 has to be 235, 9, 185:

But Chroma::Color#rgb returns 9, 185, 196:

Chroma::Color.new('#EB09B9C4').rgb
=> #<Chroma::ColorModes::Rgb:0x00007fac8de02a40 @a=0.9215686274509803, @b=196, @g=185, @r=9>

Solution

I have found a six-year-old issue jfairbank#6, that was resolved by replacing the order of arguments for FromHexStringValues#from_hex8 method. I have moved it back, and now it returns the expected RGB:

Chroma::Color.new('#EB09B9C4').rgb
=> #<Chroma::ColorModes::Rgb:0x00007fabb83d8e78 @a=0.7686274509803922, @b=185, @g=9, @r=235>