Unfortunately, accessibility is not one of designers priorities while developing web sites, resulting in barriers for numerous disabled users. In this context, it is fundamental to identify the difficulties they may experience while surfing web and to propose solutions in order to remove them or diminish their impact. The choice of colors is far from being a random process but often a way to transmit or emphase information. This is particulary true for textual information contained in a web page. The perception of colors by a dichromat user is different. This results in a loss of the information conveyed by color. In our study, we show that there is a significant loss of contrast for a dichromat user resulting in information loss. We propose a method based on a mass-spring simulation to modify the colors with aim to enforce similar contrast for dichromat users. Tests on several websites allow us to conclude that our method significantly reduce the loss of contrast for both protanope and deuteranope users.