This Little Piggy, Oil on board, 6x6

I switched to oils mostly because of the color shift with acrylics. There are some things I like about acrylics like they dry fast and are easier to transport.Especially large paintings. Also,my experience with acrylics is the acrylic polymer is somewhat milky in color when wet but dries very clear and not yellowing. This means it's like looking at the pigments in clear glass rather than the slightly amber with oils. I like the slow drying of oils for and you can easily make complete corrections by wiping off and painting over areas. The method I've been using is to tone the ground before painting. This can be good because the ground color shows through and looks nice against it's complement. Hover, I find that the ground color with oils, if it's not dry when you paint on top, tends to seep thorough and darkens the top colors. I notice that some other artists using this method don't have this problem. With this painting I used a burnt umber ground. Advice welcome: