Ok so I have always thought like most people that Blue Crash and Cool Summer Day are just two names for the same wash. I am selling my cool summer day to size up. I bought a size up in Blue Crash and I now have them both here at my house. Now that they are together I can see that there is certainly a difference. While there is no difference in the distressing there is a difference in the tone and contrast. The Cool Summer Day has more a brown tint and is less contrasty than Blue Crash. Blue Crash is more contrasty and has a blue tint. So there is the difference. They are two different washes after all. I have taken some pics for you to compare but keep in mind that in these pics its still not as easy to tell the difference (though it can be seen). In person the difference is VERY obvious. In my opinion I like the brown tint of cool summerday better but I like the deeper contrast the blue gives to Blue Crash. Blue Crash on left side and Cool Summerday on the right:
