Here is the foliage only version you've requested, I post them as a separate mod so its own updates will not alert the full terrain recolour package.
Should be graphical glitch-free with vanilla and all existing terrain recolours, it will overwrite all of their foliage. However, the colour template is designed to match with Stardew foliage redone's own terrain recolour, I have not tested how they look with other map recolours, but feel free to post your results for others to see.
More in-game footage here.

The beach map is made by me, edited based on Hidden Spirit Cove Farm, included in an upcoming story expansion mod.

Features: 

. Remodelled all the trees(including farm trees), bushes, grasses and some giant flowers to make them look more natural and realistic.
. Randomize patches of grasses with latest content patcher features, there are 11 grass and flower types per each season.
. Added more shades to trees and bushes to make them look three dimensional.
. Increased visibility of grasses.
. Supports all language versions.

Config Options(Change them in "config.json" file):

"RandomGrass": "true/false"
(enable or disable random grasses.)
"Grass": "true/false"
"GeneralBush": "true/false"
"FruitTrees": "true/false"
"GeneralTrees": "true/false"
(enable or disable forgable trees.)
"StaticTreesandBushes": "true/false"
"BloomingSpring": "true/false"
(switch between pink white trees -true/green trees with small flowers -false.)

Credits:
Forgeable trees are edited based on Eemiestardew's Just another map recolour and Rue's Creepy Curios and Spooky Aesthetics.
Fruit trees are edited based on Chisami's reshape.
Grasses are edited based on Eemie's Wildflowers.