lilac primrose

how to get the best from yellow lilac in colour it is the primrose

Sorry David, I'm not sure what you are asking

i'm trying to say what is the best way to enhance the colour of the lilac

With almost all plants the colour is fixed in it's DNA. You can bleach out the colour of some plants such as clematis by siting them in full sun, though you wouldn't want to You can change the colour of hydrangeas by changing the pH of the soil, but whatever colour your lilac is, I reckon that's how it's going to stay.

thanks canyou help why does my yucca flower late autumn early winter instead of the summer david

Don't know anything about yuccas really, but in the right conditions some can flower twice, in spring and autumn. Their flowering is irregular, depending on variety and situation.