You can buy rolls of electrical tape in a variety of colors & widths.
Some are packaged several rolls of various colors in one set.
Others are purchased individually. Look for vinyl tape. It covers. Others show under color of tube.[bleed through, they don't cover well. cheap yellow tape over a black tube looks green for instance] Quality stuff will look yellow.
I also use cut offs from weeding vinyl decals.[the part you pull off after cutting that leaves the actual decal]
All big box stores with electrical dept. have these colored tapes.
I also use automotive pin stripe tape for thinner lines and nose cones where ya need to do curved surface.[Pep-Boys, Napa even Wally world had some in auto dept.]
It always helps to increase color definition between 2 colors if you put the correct color stripe between them.
It will enhance & intensify the 2 colors more than if they just were touching.
I spent many years color matching & coordinating weird colors on Historic Victorian house's & projects . You can make just about any colors work with the right accents, to pull it all together.
The rockets below utilize all 3 elements mentioned above.
Things like putting some letters on at different angles [shifter in Shape Shifter] denote motion & give you a different effect. Adding yellow accents give "pop".
Wrapping the white checkerboard ends with black gives definition, ties in the black fins & NC tip.
Adding more yellow accents by fins gives the rear more "weight" [balance]
The orange and gray are separated by black & white stripes. Black for definition & white to make it "pop" You don't even notice the white....but it's there.
Simple things make a good looking project a great looking one!
Darker colors [two tone rockets] used at the bottom half rather than top give "weight" to the project and are more pleasing to the eye.
Never divide 2 colors exactly in half. Always use the 2/3's rule and carry one color down farther.[even if it means taping off a tube rather than stopping where the joint is....laziness]
Darker color makes rocket look thinner.[skinny]
Lighter colors make it look fatter [larger]
Many times I will extend the NC color down onto payload section, several inches, giving the illusion the NC is longer,which is also more balanced and better looking. [depends on color and length of rocket]