helm, i say, "yes"... the depth of the plate looks much more like it is bending upwards to accept or embrace the contents (perspective of plate achieved).
i really like these pieces, and they happen to be some of my favorite ^_^. cali rolls are customarily made with the rice on the outermost layer, but ive seen them done either way ( i assume its easier to make just wrapping the rice on the inside perhaps). the tamago is my favorite one, its accuracy and colors are primo and i think it best represents the food its trying to illustrate in an accurate, yet colorful/stylized manner.
the shrimp sashimi has wonderful colors, though i find the shape of the shrimp itself looking a bit too rectangular in nature. i am aware that the belly is slit and is spread out to take the shape of the rice, but in my memory it looks more like a triangle ontop than a square. i knwo if i were personally coloring these i would shift the hue from the orange to apink when going from lighter tones to darker ones, i think that would look especially good on these here shrimpies (slurp)
the only one that seems not very strong to me is the temaki... usually the contents are gushing out the top in an artful manner from what i can remember, yours dont really look 'full' or 'wrapped' as much as they do 'stuffed', if that makes sense. theyre supposed to be very non symmetrical by nature and i can only best describe the contents pouring out like a 'boutique'.
i think your understanding of color is certainly up there, these are fun pieces to look at in general.
oh one last thing there, if you are going for a less shiny/plastic feel, perhaps throw in some texture... also the playful, artificial blue color used for the plate might not really help the illlusion, perhaps switching to a dark green or a deep red (though not overly saturated) would help.