I can't see if your cushions are red or pink, but the other stand-out colour is the bright green. Try clicking those 2 colour boxes on artfuly.com and perhaps use the size sliders too, to see what comes up for that back wall I see in your photo. Some white also may be good if the walls are an off-white.

I'd agree with adding darker colours to the mix... if reupholstering things is not in the budget just by adding chocolate, charcoal or navy blue to the chair and bedding will help. Add some rougher textures, chunky knits, pin stripes, vintage linen and right on trend velvet.... Adairs have a sale for another couple of days on their linen and other products https://www.adairs.com.au/search/?q=Vintage+washed+linen Accessories to consider are things made of dark marble, timbers, geometric shapes and gold... A bold feature wall could give some mood to the room again in the above colours.

Removable wall decals would brighten up the walls. You could change the kitchen cabinet handles and change them back when you move out. It's surprising how much difference new handles make. Lighting makes a huge diff - maybe change the lampshade or add some floor lamps? I agree with others about area rugs (climate permitting). Also some indoor plants never go astray.

I suggest the very first thing to do , would be to decide your budget and what you want to achieve , and to a certain degree what the suburb is like ? If it's the 'worst' house in an upmarket suburb , then $100K or even $200k may really lift its value , but if its in a 'cheaper' suburb , you may over capitalise . Like others , some things I'd look at -- -- Do the gardens , trim the tree , looks more like rank grass along the side of the driveway ? Maybe a white stone garden , with a Yukka ort similar . -- The concrete driveway looks 'drunk' , but that may be because of the shapes it was laid in ? Level it , take the front out to the street , talk to an expert about doing a one-run top coat of concrete . -- Remove the fairy lights , relocate the satelite dish . -- Personally , Id frame upwards on the top of the carport and lounge roof , and also the first floor roof , and put bright 25-30cm tall painted or powder coasted alloy panels -- cover the gutters and 'hide' the solar panels . Paint or coat them whatever colour you like , but I'd go for something like bright yellow or orange or red , mid blue , a crisp green ? -- Someone suggested brown wooden 'louvres' full-length over the upstairs windows . I'd be tempted to go with that idea ( buy 30mmx30mm pine , and a mid brown stain -- 6 or 8 'rails' along that upstairs on the side and front you can see in the pictures . Instead of mid-brown stain , a black/charcoal may suit better , especially if you go with those bright panels . -- Maybe a fence in the same 30 x 30 horizontal wood , same stain colour -- ties the upstairs to the 'ground' level ? Relatively budget , and can be done in several steps , but would 'lift' it no end IMO .