Hello people.
I'm vectorizing the Spanish suited playing cards, and there it is, this big problem that is driving me crazy.
Take a look at this image:

Note the "fuzziness" in the transition between red and yellow... I have no idea how to do that with vectors... and I'd like it to be only vectors.
I've tried different approaches, like creating multiple objects, applying gradient fills and then adding some blur... but it doesn't look good. I can't reproduce the effect. I understand that it won't look exactly like this, because it's a vector image... but I would like to achieve something similar...
Does anyone have a some ideas to do this? Suggestions?
Thanks for your time and help.
Bye.