Get rid of Inkies and hit the Second Tranforms. 

The Twenty-sixth Challenge is quite simple.  You just need 50 purple paint points to transform ink into water.  Red and Blue are nearby, and this will open up a lot of challenges.  This is the Fourth Landmark. 

Ignore the blue arrow, and go to the green Challenge near it.  What you need to do is paint 15 trees in one of the areas below.  This is only difficult because the last three are surrounded by water.  The way to access them is to take the Z-point, and then launch to get to them.  Work your way down the back of a building and color the first one, and then the last two.  This will bring your Tree Total up to 39.  By the way, this path will collect you the Eleventh Style, and you can color the Twenty-second Billboard and Twenty-third Billboard.  You should also color in all the building blocks down here, as you can release the Twenty-fourth Raydian Batch and the Twenty-fifth Raydian Batch for a total of 230. 

Go back up to the area with the Fourth Landmark.  The Twenty-eighth Challenge involves painting some area green and another purple.  I would paint it green first, and make certain you get the Twenty-fourth Billboard.  If you color it all in, you can free the Twenty-sixth Raydian Batch for a total of 238.  Be certain that when you paint the other side purple, you get the Twenty-fifth Billboard. 

The Twenty-ninth Challenge is another marker puzzle that pits you by doing Z-jumps.  It is quite simple, really. 

Fourth Area

The Thirtieth Challenge is another marker, and it is quite simple again.  Just hit the lever before you go on any hot burners, and you’ll be fine. 

This leads to the Thirty-first Challenge, which is just getting rid of Inkies.  Nothing you haven’t done before. 

At some point in time, the Third Transforms will reveal itself inside the courtyard.  Go ahead and pounce it. 

The Thirty-second Challenge is right near there.  It involves painting an upper level green and a bottom level blue.  I would concentrate first on the green on top, because you will have to stand on the areas you need to paint blue.  Once that is painted green, wash off with a nearby pool and paint the rest blue.  By the way, the Twelfth Style is here, as well as the Twenty-sixth Billboard.  Why not free the Twenty-seventh Raydian Batch for a total of 246?  You should also paint the 2 trees here, giving you a Tree Total of 41.