In ~/.Xdefaults:

Aterm*background: #404056
Aterm*foreground: #c0c0e6
Aterm*color0: #000000
Aterm*color1: #f596a0
Aterm*color2: #80d0f0
Aterm*color3: #c3b3f3
Aterm*color4: #9565c2
Aterm*color5: #c3b3f3
Aterm*color6: #80d0f0
Aterm*color7: #c0c0e6
Aterm*color8: #b0b0d6
Aterm*color9: #ff96a0
Aterm*color10: #00d0c0
Aterm*color11: #ad9ce2
Aterm*color12: #a0a0f0
Aterm*color13: #ad9ce2
Aterm*color14: #70c0e0
Aterm*color15: #d0d0f6
Aterm*colorUL: #a0a0f0
Aterm*colorBD: #e0e0f6
Aterm*cursorColor: #ffffff
Aterm*cursorColor2: #000000
Aterm*scrollColor: #a0a0f0
Aterm*troughColor: #8080e0
Aterm*reverseVideo: False

in ~/.xinitrc:

xrdb -load $HOME/.Xdefaults