If you need to make textures that resemble roads and corners u need to make each corner prerendered as a tile for each rotation currently until we get rotate matrix tile or something similar.
in order to blend two colours these are the combos required.
eg green and brown
full green suare
full brown square
half brown/green vertical
half green/brown vertical
half brown/green horizontal
half green/brown vertical
now if you want corners
green with a brown curve in the left bottom corner
brown with a green curve in the left bottom corner
green with a brown curve in the right bottom corner
brown with a green curve in the right bottom corner
green with a brown curve in the left top corner
brown with a green curve in the left top corner
green with a brown curve in the right top corner
brown with a green curve in the right top corner
now if we had a way to rotate the tiles we wouldnt need to make each rotation as its own tile in a series.
If we had rotate matrix tile we can reduce the amount of combinations to 3
1 full colour / 1 half half colour / and one corner tile of two colours.
rotating these 0 / 90 / 180 / 270 will alleiate having to create every tile combo as well as increase the pixel space per tile.
As you can see this gets very complicated but its possible.
I have 5 colour combinations in my matrix editor and it took a lot of blood sweat and tears to work this out.
It looks like your using a plain for some reason i cant fathom yet.