I've always said a triple rail fence quilt is one of the quickest, easiest to do; when you finish sewing the strips together, cut the block sections out and the quilt is virtually done! Color placement is what makes these quilt so appealing.
Here are three I designed. Two are just graphics - ideas done in MSPaint program, one other was sold in Austin, TX 10 years ago.
Notice that the colors are "graded" -- the reds, for example, range from dark red, to true red, to lighter red. The blues do the same. The 'whites' are 3 different ecrus, or white tone-on-tones, or, preferably, shirting prints. This makes the rails coherent and keeps the pattern from looking "jittery" over all.
I suggest choosing a theme print for your larger border (and maybe the backing!), then choosing your other colors from the theme print.
Jan in VA