I'm breaking a rule by posting two pictures, but I'm trying to figure something out. Most of my pictures are taken on my camera's "auto" mode, which means I don't decide anything but what to point the camera at and when to press the button. But when I've experimented with setting the aperture or shutter speed myself, I've noticed that not only does it change whether the picture looks washed out or too dark, but also influences what the colors look like. But I haven't figured out yet how to get colors that are exactly like what I see when I'm looking at the real thing.
These two pictures are of some clouds right after sunset. I wanted to see what would happen if I adjusted the shutter speed. The picture on top was taken with a shutter speed of 1/3 second (the camera automatically set the aperture to f/4). The one on the bottom was taken just after the first one, I set the shutter speed to 1.3 seconds and the camera set the aperture to f/4.5. The colors on neither of the pictures look like what I actually saw when I was looking at the sky.
It seems like this is very basic level photo knowledge, but I'm not quite getting it. Can someone explain what's going on? Why does the first picture look almost black and white? Why did longer exposure make the colors become way more vibrant and more blue than what I saw in real life? What would I have needed to do to get the pictures as true to life as possible? Unfortunately I didn't take a picture just on auto mode, but with other pictures in auto it seems that colors are kind of washed out a bit.