Basic colors
Here are some colors that work well together.
Dark red and green on yellow
Heading color: #660000
Heading color: #006600
Normal text color is black. Background is #FFFFCC.
Blues on yellow
Heading color: #000066
Heading color: #0066FF
Normal text color is black. Background is #FFFFCC.
Change the last two hexadecimal digits of the background color to make different yellows. The higher the number, the lighter the yellow. So #FFFF88 is a more saturated yellow, #FFFFAA is lighter, and #FFFFDD is lighter still.
Grays
Heading color: white. Background is #444444. Needs padding to look right.
Heading color: #444444
Normal text color is black. Background is white.
Any color where all of the hexadecimal digits are the same will be gray. The lower the digits, the darker the gray. So #333333 is darker than #888888 is darker than #CCCCCC.
Exercises