Grid

i The grid has flexbox under the hood, you can explore the sass files and find some nice helper classes.
Container
Container Fluid

Colors

i Play with colors and color variants in the config file.
{state}:{color}-{fill|text|border}:{variant}

Fill Colors

Pick a variant and you're good to go. The base variant is 500. This system follow google's material colors guide.
.red-fill:50.hover:red-fill
.red-fill:100
.red-fill:200
.red-fill:300
.red-fill:400
.red-fill
.red-fill:600
.red-fill:700
.red-fill:800
.red-fill:900
.green-fill:50.active:green-fill
.green-fill:100
.green-fill:200
.green-fill:300
.green-fill:400
.green-fill
.green-fill:600
.green-fill:700
.green-fill:800
.green-fill:900
.blue-fill:100
.blue-fill:200
.blue-fill:300
.blue-fill:400
.blue-fill
.blue-fill:600
.blue-fill:700
.blue-fill:800
.blue-fill:900
.gray-fill:50
.gray-fill:100
.gray-fill:200
.gray-fill:300
.gray-fill:400
.gray-fill
.gray-fill:600
.gray-fill:700
.gray-fill:800
.gray-fill:900

Text Colors

Same technique as fill but these change text color instead of background.
.red-text:50
.red-text:100
.red-text:200
.red-text:300
.red-text:400
.red-text
.red-text:600
.red-text:700
.red-text:800
.red-text:900
.green-text:50
.green-text:100
.green-text:200
.green-text:300
.green-text:400
.green-text
.green-text:600
.green-text:700
.green-text:800
.green-text:900
.blue-text:50
.blue-text:100
.blue-text:200
.blue-text:300
.blue-text:400
.blue-text
.blue-text:600
.blue-text:700
.blue-text:800
.blue-text:900
.gray-text:50
.gray-text:100
.gray-text:200
.gray-text:300
.gray-text:400
.gray-text
.gray-text:600
.gray-text:700
.gray-text:800
.gray-text:900

Border Colors

Same technique as fill and text but these change border color. Ex: .b{l|r|t|b|none}-{size}:{variant} .{color}-border
a
a
a
a

Gradient Colors

Gradient classes are generated by the index number in the config file and it starts from .grad-0. Ex: .grad-{index}
.grad-0
.grad-1
.grad-2

Fonts

Lorem ipsum dolor sit amet, consectetur adipisicing elit. Corporis, beatae?
Lorem ipsum dolor sit amet, consectetur adipisicing elit. Corporis, beatae?
Lorem ipsum dolor sit amet, consectetur adipisicing elit. Corporis, beatae?
Lorem ipsum dolor sit amet, consectetur adipisicing elit. Corporis, beatae?
Lorem ipsum dolor sit amet, consectetur adipisicing elit. Corporis, beatae?
Lorem ipsum dolor sit amet, consectetur adipisicing elit. Corporis, beatae?

Box

Paddings

Padding
.p-{value}
Padding top
.pt-{value}
Padding bottom
.pb-{value}
Padding left
.pl-{value}
Padding right
.pr-{value}
Padding horizontal
.ph-{value}
Padding vertical
.pv-{value}

Margins

Margin
.m-{value}
Margin top
.mt-{value}
Margin bottom
.mb-{value}
Margin left
.ml-{value}
Margin right
.mr-{value}
Margin horizontal
.mh-{value}
Margin vertical
.mv-{value}

Utilities

border-width
.b-{px}
border-radius
.rad-{px}
width
.w-{px}
height
.h-{px}
positions
.{left|right|top|bottom}-{px}
z-index
.z-{px}
shadow
.bs-{px}

Tips

Adding too many colors and utilities can result in large css output.