It had a pretty standard color scheme in use among African countries, based on the colors of the Pan-African movement. It also added a sun at the top, in red. I think Malawi's old flag was decent, although I never liked that sun being red. It made the flag too dark overall, and did not stand out enough.
Now Malawi has a new flag, though there is some debate how long it will last:
The color scheme was maintained, which is good, and the usage of the sun as a symbol to help distinguish the flag remains. Overall these were good ideas, and changing the color to white does brighten up the flag significantly.
Still, I think problems remain. The white is too striking a color. Malawi should have gone with yellow or gold instead, creating a flag reminiscent of the now defunct Biafra. Maybe though, that is what they were trying to avoid. I think having so many rays around the sun is distracting and makes it hard for people to replicate the flag. One of the cardinal rules of flag design is to make flags simple enough for children to draw. On this basis, both the flag of the United States and Malawi fail, too many unnecessary little pieces. A white circle set inside another one empty in the middle would have sufficed.