You're on your own for color choices for the flowers. There's thousands of suitable colors to choose from, so 'pick' your own flowers! LOL Picking the right green can sometimes be difficult, so two color swatches for 'greens' have been provided. The 'TREES' swatch has some muted shades of green for background foliage, while the 'VINE' swatch has some greens that are a little brighter. You can use these greens for foliage or pick your own. You could mix in some browns, maroons, golds and yellows too.
Climbing Roses:
Create a new raster layer for ROSE VINE that is above all other layers. With the darkest green, scribble a vine twining around the porch posts and up over the top of the gable and along the roof. With a couple more shades of green, paint some lighter colored 'leaves' here and there using a 1 or 2 pixel brush. I tried painting some tiny fussy leaves on the vine, but at this small size it was hard to tell the difference between the leaves I drew and the areas that were just scribbled in. Scribbling is faster!
Add some red roses to vine. With a size 2 or 3 brush and some rose red, plop in some flowers all over the vine. Use a very light shade of red (pink-red or orange-red) and a 1 pixel brush to highlight each flower.
Window Boxes:
Paint some more greens from VINE swatch in the window boxes. Add some flowers in color(s) of your choice with a 2 pixel brush. Group some of these posies together. Paint some highlights along top of flowers with the same pink-red or orange-red.