I found this graphic from an adobe article which taught readers about vector graphics. It first intrigued me because of its colors, and then how crisp the lines were. Obviously this is a jpeg version of the vector, but I imagine the vector file to be even crisper.

Though there are only 8 colors total in this graphic, it feels like there are more simply because of how the designer used each color. The off-white in the background of the image naturally draws our eyes closer to the center where the bird is, and the bird has a gradient of color on its body that promote subtle details you would normally see on a real bird. Every shape is blocked out in their own colors beyond those gradients, yet, it doesn’t feel like you lose detail in the color. 

The gradient on the bird's body going from light at the top to a darker shade at the bottom gives the impression of sunlight hitting the top of the bird's head. 

The off-white background color is connected to the smaller graphic as a line goes through the yellow circle. The designer also made great use of warmer and cooler colors that were different enough to create depth, but not too different to create clashing elements. 

The pleasing use of proximity is apparent in the "white space" between the bird and the rest of the graphic as well as the bird's closeness to specific shapes. 

In some areas, the body of the bird has substantial distance from the edge of the yellow circle. The bird's beak and tail stretch beyond the yellow circle. This contrast of proximity creates a pleasing line from the top left corner of the graphic to the bottom right.

The proximity of the bird's claw and the white line stretching across the yellow circle is also something to be noted. There are no gaps between the claw and white line that show any yellow through. This gives any viewer the impression that although they are different colors, these objects within the graphic are connected through proximity. 

No two versions of the same color are touching, which creates a contrast that allows the viewer to see the graphic's details more clearly. Instead of using a contrasting color in the stroke to highlight certain shapes, the designer used the same color stroke as the shape itself. There is also a subtle contrast between the off-white background color and the white color of the bird's neck. It is subtle enough to draw the viewer's attention to the bird rather than the background.

The shape of the pointy beak and claws compared to the smoother pointed tail also present a nice contrast of shape.