Custom color gradient control class for perlineffects

Hi, You will notice when trying to make nice perlin maps that you have to set the input colours manually. This is a pain in the hole as you have to recompile each time to see the result. So after trying to create the perfect fluffy clouds for the 20th time in a row it occured to me:

Is there any custom class out there looking like the following that some of ye guys might have seen:

Basically it would be a control panel for creating a series of alpha, rgb and distance position values for a linear gradient that I could then dump into a Bitmap data and stick into my perlin maps.