Slydev has a decent range of colors which is growing all the time. Though there is no real way to tell exactly what color something from looking at a photo, this page will describe the colors and show how they relate to various nerf blasters for better reference.
Note: Colors may vary slightly from the pictures below due to different suppliers. Some newer colors have yet to have parts printed and be compared to blasters

Black

Black is easily the most popular color. There is not much to say about it as black is pretty much universal, it matches with most other things and has a great finish. Here printed black parts are compared to a variety of scopes, black painted maverick, xplorer longshot grip, flip clip and a stampede front handle.

Blue

Blue is a lot lighter than most nerf products. I am sorcing a darker more navy blue for the future to match nerf products better. Here printed blue parts are compared to a blue longshot, maverick and a raider stock.

Carrot

Carrot is well a carrot like orange color. It is a bit lighter than the other orange Slydev offers and matches nerf products quite well.

Clear

Clear is one of the more unique 'colors', while the filament is clear it actually has a 'cloudy' look because of the 3d printing process. It looks awesome as is but even more awesome when light is projected through it.

Dark Blue

Dark blue was aquired to find a blue that was closer to nerf products however while it looks close in the photo this blue is actually quite a lot more 'green' than the nerf blue. Still looks quite nice on blue blasters.

Light Grey

Discribed as 'deathstar grey' this grey is quite light but really matches the elite blaster range.

Dark Grey

This grey is a darker grey than the other one on offer, matches most blasters well.

Fairy Floss

This is a very bright pink which is more 'purple' like than the other pink the Slydev store offers.

Glow in the dark

Glow in the dark looks like white under normal light but glows the same green as the glow in the dark blue when in darkness. It reaches maximum glow exposure in about 10 seconds under direct light and then will dim fairly quickly within the first 10minutes, after then it starts to slowly glow less.

Glow in the dark Blue

Glow in the dark blue is a baby blue color under light but in darkness it glows a bright green. It reaches maximum glow exposure in about 10 seconds under direct light and then will dim fairly quickly within the first 10minutes, after then it starts to slowly glow less.

Gold

Gold is a nifty color with a nice shine, however it is more of a 'bronzy brown gold' than a pure gold. Looks quite different depending on the lighting.

Green

Green is quite bright, though matches very well with nerf products.

Temp Change - Green to Yellow

This plastic changes color when it becomes hotter, going from a dark green to a nice yellow when it reaches about 30 degrees.

Temp Change - Grey to White

This plastic changes color when it becomes hotter, going from a dark grey to a white when it reaches about 30 degrees.

Temp Change - Purple to Pink

This plastic changes color when it becomes hotter, going from a dark purple to a pink when it reaches about 30 degrees.

Natural

Natural is best described as a 'bone white'. Is a good base color if you intent to paint the parts later. (Note: Acetone based paints will destroy slydev parts)

Orange

This orange is Slydev's second most popular color, it is quite bright and is best described as a 'saftey' orange.

Pink

A more 'red' pink than the other 'fairy floss' color

Purple

A nice bright purple

Red

A nice bright red, matches nerf blasters quite well

Clear Blue

A seethrough dark blue which looks great when light is put through it

Clear Red

A seethrough red which looks great when light is put through it

White

A nice thick white, matches elite blasters quite well.

Yellow

A bright yellow which is a bit lighter than the nerf yellow.