iOS different colors in one canvas

i just started learning xojo a few weeks ago.
Currently i’m designing the UI for my app.
Here is my problem:
I have one canvas element and would like that it has a round rectangle shape with an grey color, and in this element there should be text with a different color.
I know how to create this things within an canvas element, but i don’t know how to give them different colors.
Thanks in advance for you help.

The Graphics code of a paint event is linear, not object oriented in the meaning that later settings do not influence previous code. So you can set graphics.forecolor to a value, paint the background, define forecolor differently and draw the Text.