text color in python-pptx module

Add them as separate runs like so:

from pptx.dml.color import RGBColor
from pptx.enum.dml import MSO_THEME_COLOR
from pptx.util import Pt

p = tf.add_paragraph()
run = p.add_run()
run.text = 'hello'
font = run.font
font.name = 'Calibri'
font.size = Pt(18)
font.bold = True
font.color.theme_color = MSO_THEME_COLOR.ACCENT_1

run = p.add_run()
run.text = ' is red and the rest is blue'
run.font.color.rgb = RGBColor(0, 0, 255)

A run is a sequence of characters all sharing the same character formatting. To change character formatting within a paragraph, multiple runs must be used.