Ask HN: Is there any psychology behind consistently lightening color choices?

I saw some discussions earlier today surrounding http://flatuicolors.com/ and http://www.flatuicolorpicker.com/. This got me thinking about my color choices and I wanted to get some opinions.

I use several of the colors listed on Flat UI: alizarin, nephritis, and sun flower. I often need a lighter/darker variant of the colors. To do this, I apply LESS' "lighten" and "darken." My colors end up looking like:

    @baseBlue: rgb(78,166,234);
    @lightBaseBlue: lighten(@baseBlue, 30%);
    @darkBaseBlue: darken(@baseBlue, 10%);

    //  http://flatuicolors.com/
    @nephritis: rgb(39,174,96);
    @lightNephritis: lighten(@nephritis, 30%);
    @alizarin: rgb(231,76,60);
    @lightAlizarin: lighten(@alizarin, 30%);
    @darkAlizarin: darken(@alizarin, 10%);
    @sunFlower: rgb(241, 196, 15);

Is there any psychological benefit associated with lightening/darkening each color by consistent percentages? Sometimes I feel like a color looks 'off' when lightened. For instance, lightNephritis feels like it has a bit too much blue in it, but I'm happy with nephritis. However, I also feel weird about just choosing a new 'lightGreen' color instead of lightening my base color.

Thoughts?