c# - Increase Hex colour by xx%

Question

I allow my users to set a background colour in their app (ie #D900D9), which is stored as a string. I then would like to set a property, 'border' which will take the hex value 'background' and the darkness say by 20%?( ie #770077) How can I achieve this?

public string backgroundColor { get; set; }
 public string borderColor
        {
            get
            {
                return backgroundColor + 20%
            } 
        }

nope, I just dont where to start, lots of RGB examples, just wondering if something simple existed out there? — D-W, Apr 05 '17 at 11:28

score 2 · Answer 1 · edited May 23 '17 at 12:17

2

You'd need to create a Color object

var yourColor = Color.FromHex(backgroundColor);

And then just factor the RGB values:

var c2 = Color.FromArgb(yourColor.A,
    (int)(yourColor.R * 0.8), (int)(yourColor .G * 0.8), (int)(yourColor.B * 0.8));

(which should darken it; or, for example, * 1.25 to brighten it)

Credits: How do I adjust the brightness of a color? (@Marc Gravell)

edited May 23 '17 at 12:17

Community

1
1

answered Apr 05 '17 at 11:32

greenhoorn

1,601
2
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score 0 · Accepted Answer · answered Apr 05 '17 at 11:49

public string backgroundColor { get; set; } 
public string borderColor
        {
get
            {
                Color c1 = System.Drawing.ColorTranslator.FromHtml(backgroundColor);
                Color c2 = Color.FromArgb(c1.A,(int)(c1.R * 0.8), (int)(c1.G * 0.8), (int)(c1.B * 0.8));
                return System.Drawing.ColorTranslator.ToHtml(c2);
            } 
}

c# - Increase Hex colour by xx%

2 Answers2