In response to
>>1262 I'll make a brief post about why colors were so damned good in cel animation versus modern productions.
1. Paint
They're quite literally using real world paints on plastic cels to photograph so the colors are much better quality and more realistic.
2. Film stock
They were shot on 16mm or 35mm film, and film stock had strived for decade for rich strong colors and strong contrasts. Most television anime was shot in 16mm film, and 35mm used for theatrical films or television OPs.
Then they shifted to digital formats, and with them digital color spaces and palettes. More washed out, lacking contrast, overly bright, like there's a haze or some kind of bright light out. This is also an issue for live action productions.