Those are stars. They show up as round blobs rather than sharp points because your camera wasn't accurately focused to infinity.

(In the comments it was suggested that your lens may have been focused past infinity, which sounds plausible to me since no part of your picture seems to be in focus. If your focus had been too close, at least some parts of the foreground should be in focus.)

The blue and yellow colors are the actual colors of those stars, which primarily depend on the star's surface temperature. (The blue stars are the hottest, the reddish ones are less hot.)

While you could fix the "blobbiness" by focusing your camera lens better (tip: use manual focus, don't rely on autofocus for dark scenes like this!), you might also want to consider instead leaning into the blurry effect and deliberately defocusing your camera even further.

Defocusing the stars like you've done here is actually a great way to bring out their colors, which are normally hard to see since the stars are sharp bright point sources of light that tend to saturate camera sensors (or film) if they're perfectly in focus, making them all look like just tiny white dots.* Defocusing the stars spreads their light over multiple sensor pixels, preventing any individual pixel from saturating while still leaving the stars clearly visible (as colored circles, or other shapes depending on your bokeh) in the final image.

With some luck, skill and experimentation, I think you could end up with a very pretty and dreamlike (and informative!) image. Here are a few links to some sample images I found by googling for "milky way bokeh", illustrating the kind of photos you might be able to get:

• https://www.instagram.com/sky.n.pixels/p/C5YeBqdtfqf/
• https://www.shutterstock.com/image-photo/blurry-bokeh-milky-way-bright-stars-1960852321
• https://pixels.com/featured/milky-way-bokeh-dustin-goodspeed.html
• https://www.matthewlandonimages.com/nightscapes
• https://c.realme.com/global/post-details/1455935605741531136

(These are all copyrighted photos by third party photographers, so I won't embed them here. Just follow the links or run your own search.)

If you'd like to combine these blurry stars with sharp foreground details in your photo, you could try taking two images, one in sharp focus and the other our of focus, and combining them in postprocessing. Or just take a single long exposure with manual focus and adjust the focus during the exposure. With some practice, you can even use this technique to create effects like these extremely cool variable focus star trails.

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(*) This is also why you never actually want stars to be perfectly sharp and in focus, since if they are, all bright stars will just show up as single white pixels with no way to distinguish them by brightness or color. Depending on the demosaicing algorithm your camera or RAW converter uses, you can also end up with weird color effects as noted in the comments below.

To avoid these issues with bright point sources like stars, it's better to either focus your lens just a little bit short of infinity or to use a mild diffusion (or, for a more artistic effect, starburst) filter to spread the light of bright stars over multiple sensor pixels. (Of course cheap cameras with low quality optics may do that without any help.)