VS 2010 Gradient Color Text Tool - Strings And Numbers

I am making a gradient colored text tool for a game I play where they use a 3 digit number as an RGB color code before text. Making gradients by hand is tedious, as to do a gradient you type one letter at a time with an RGB code that changes by 1 in front of each letter.
example: "^090H^190e^290l^390l^490o" Would be a color gradient for Hello

I have a user input text into a text box and choose up to 6 colors. The colors then are assigned RGB values, only instead of 0-255 they are 0-9. (So they look like this 000=black 999=white 090=green, etc.)

I have figured out how to do this, but now I need to place the RGB values in front of the users text while only changing one of the RGB numbers at a time.

So if the color values are 090 and 900:
"090 190 290 390 490 590 690 790 890 990 980 970 960 950 940 930 920 910 900" is what I would like generated with the users text spaced evenly between.

I have no idea as to how I would go about putting three digit color codes between the users text or how to change the color codes one number at a time. I could try to do this on my own but it would be sloppy and probably a lot more code than needed (I have a feeling I should be using a loop or something like 'for each')... It's been awhile since I opened VB!